{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:10:29Z","timestamp":1785424229165,"version":"3.56.0"},"reference-count":115,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T00:00:00Z","timestamp":1785196800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008227","name":"University of South Africa","doi-asserted-by":"publisher","award":["90546210"],"award-info":[{"award-number":["90546210"]}],"id":[{"id":"10.13039\/501100008227","id-type":"DOI","asserted-by":"publisher"}]},{"award":["90546210"],"award-info":[{"award-number":["90546210"]}],"id":[{"id":"https:\/\/ror.org\/048cwvf49","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmaceuticals"],"abstract":"<jats:p>Hollow glass microspheres, as demonstrated in recent studies, have shown significant importance in the field of composite materials and have emerged as transformative materials in biomedical applications. This is necessitated by their ability to provide a physicochemical gradient, a desirable tool for complex tissues and biological interfaces, through the spatiotemporal release of bioactive factors and nanophase ceramics. HGMs are structures with diameters ranging from 1 to 1000 \u00b5m that can be used as support for cell growth, either in the form of a scaffold or a drug delivery system. In this review, we describe the various methods for HGM fabrications, synthesis (e.g., flame spraying, sol-gel processes, spray drying, etc.), structural characterizations, and chemical and physical properties (e.g., densities ranging from 0.1 to 0.6 g\/cm3 and compressive strength ranging from 10 MPa to 30 MPa for low and high densities, respectively), highlighting how these methods influence their drug delivery, tissue engineering, bone implants, and nanocarrier abilities. Furthermore, a comprehensive list of other materials and their various biomedical uses is reported. Some of the limitations of existing techniques and future investigations into how HGM can perform as a biomedical material are discussed.<\/jats:p>","DOI":"10.3390\/ph19081183","type":"journal-article","created":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T11:45:26Z","timestamp":1785239126000},"page":"1183","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Hollow Glass Microspheres (HGMs): Synthesis, Characterization, and Processes in Biomedical Applications\u2014A Review"],"prefix":"10.3390","volume":"19","author":[{"given":"Olusegun Adigun","family":"Afolabi","sequence":"first","affiliation":[{"name":"Department of Industrial Engineering and Engineering Management, University of South Africa, Florida, Johannesburg 1710, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ndivhuwo","family":"Ndou","sequence":"additional","affiliation":[{"name":"Department of Industrial Engineering and Engineering Management, University of South Africa, Florida, Johannesburg 1710, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,28]]},"reference":[{"key":"ref_1","unstructured":"Afolabi, O.A. (2023). Hybrid Syntactic Foam Core-Based Natural-Glass Fibre Sandwich Composite in Mechanical Engineering. [Ph.D. Thesis, Durban University of Technology]."},{"key":"ref_2","first-page":"613","article-title":"Glass Microspheres","volume":"6","author":"Karasu","year":"2019","journal-title":"El-Cezeri J. Sci. Eng."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1111\/ijag.12199","article-title":"Tiny Bubbles Composite Cocktails for Medical Applications","volume":"7","author":"Wicks","year":"2016","journal-title":"Int. J. Appl. Glass Sci."},{"key":"ref_4","first-page":"20","article-title":"A Comprehensive Review on Microsphere and its Application","volume":"10","author":"Kumar","year":"2023","journal-title":"Int. J. Res. Anal. Rev. IJRAR"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Afolabi, O.A., Mohan, T.P., and Kanny, K. (2023). Processing of Low-Density HGM-Filled Epoxy\u2013Syntactic Foam Composites with High Specific Properties for Marine Applications. Materials, 16.","DOI":"10.3390\/ma16041732"},{"key":"ref_6","first-page":"746","article-title":"Thermal Conductivity and Tensile Properties of Hollow Glass Microsphere\/Polypropylene Composites","volume":"2017","year":"2017","journal-title":"Anadolu Univ. J. Sci. Technol. A Appl. Sci. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1645","DOI":"10.1016\/j.acme.2018.07.008","article-title":"Effect of process parameters on mechanical properties of hollow glass microsphere reinforced magnesium alloy syntactic foams under vacuum die casting","volume":"18","author":"Anbuchezhiyan","year":"2018","journal-title":"Arch. Civ. Mech. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Wang, H., Yan, R., Cheng, H., Zou, M., Wang, H., and Zheng, K. (2023). Hollow glass microspheres\/phenolic syntactic foams with excellent mechanical and thermal insulate performance. Front. Chem., 11.","DOI":"10.3389\/fchem.2023.1216706"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1007\/s10965-023-03747-x","article-title":"Robust silicone rubber with high transparency by loading with porous hollow glass microsphere","volume":"30","author":"Li","year":"2023","journal-title":"J. Polym. Res."},{"key":"ref_10","unstructured":"Dillinger, B. (2016). Crush Strength Analysis of Hollow Glass Microspheres. [Master\u2019s Thesis, Virginia Polytechnic Institute and State University]."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Shira, S., and Buller, C. (2015). Mixing and Dispersion of Hollow Glass Microsphere Products. Hollow Glass Microspheres for Plastics, Elastomers, and Adhesives Compounds, Elsevier.","DOI":"10.1016\/B978-1-4557-7443-2.00011-6"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1016\/j.actbio.2018.03.040","article-title":"Porous Calcium Phosphate Glass Microspheres for Orthobiologic Applications","volume":"72","author":"Hossain","year":"2018","journal-title":"Acta Biomater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1007\/s10717-025-00725-1","article-title":"Composite Based on Hollow Glass Microspheres Modified With Silver Nanoparticles","volume":"81","author":"Nikiforova","year":"2025","journal-title":"Glass Ceram."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"111177","DOI":"10.1016\/j.msec.2020.111177","article-title":"NMR studies of materials loaded into porous-wall hollow glass microspheres","volume":"116","author":"Huang","year":"2020","journal-title":"Mater. Sci. Eng. C Mater. Biol. Appl."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"300","DOI":"10.1039\/D0MH01498B","article-title":"Porous bioactive glass micro- and nanospheres with controlled morphology: Developments, properties and emerging biomedical applications","volume":"8","author":"Zheng","year":"2021","journal-title":"Mater. Horiz."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"13579","DOI":"10.1016\/j.ceramint.2019.03.241","article-title":"A hierarchically porous bioactive glass-ceramic microsphere with enhanced bioactivity for bone tissue engineering","volume":"45","author":"Hong","year":"2019","journal-title":"Ceram. Int."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"5222","DOI":"10.1021\/acsbiomaterials.3c00609","article-title":"Bioactive Materials for Bone Regeneration: Biomolecules and Delivery Systems","volume":"9","author":"Urbaniak","year":"2023","journal-title":"ACS Biomater. Sci. Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2581","DOI":"10.1021\/acsbiomaterials.3c01956","article-title":"Three-Dimensional-Printed Spherical Hollow Structural Scaffolds for Guiding Critical-Sized Bone Regeneration","volume":"10","author":"Liu","year":"2024","journal-title":"ACS Biomater. Sci. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"13552","DOI":"10.1016\/j.ceramint.2021.01.214","article-title":"Recent progress on biomedical applications of functionalized hollow hydroxyapatite microspheres","volume":"47","author":"Zhang","year":"2021","journal-title":"Ceram. Int."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"690","DOI":"10.1039\/C5CS00695C","article-title":"Syntheses and biomedical applications of hollow micro-\/nano-spheres with large-through-holes","volume":"45","author":"Si","year":"2016","journal-title":"Chem. Soc. Rev."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"126667","DOI":"10.1016\/j.cej.2020.126667","article-title":"Sponge-derived natural bioactive glass microspheres with self-assembled surface channel arrays opening into a hollow core for bone tissue and controlled drug release applications","volume":"407","author":"Kaya","year":"2021","journal-title":"Chem. Eng. J."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"101885","DOI":"10.1016\/j.coco.2024.101885","article-title":"Constructing \u2018bayberry shape\u2019 structure on HGMs surface using CNTs to enhance the mechanical properties of HGMs\/epoxy composites","volume":"47","author":"Wang","year":"2024","journal-title":"Compos. Commun."},{"key":"ref_23","first-page":"588","article-title":"An Overview on Microspheres Preparation and Evaluation Methods","volume":"9","author":"Himabindhu","year":"2019","journal-title":"Indo Am. J. Pharm. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1002\/(SICI)1097-0126(200002)49:2<170::AID-PI322>3.0.CO;2-U","article-title":"Effect of filler content and surface treatment on the tensile properties of glass-bead-filled polypropylene composites","volume":"49","author":"Liang","year":"2000","journal-title":"Polym. Int."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"012022","DOI":"10.1088\/1757-899X\/205\/1\/012022","article-title":"A Comparative Study of Production of Glass Microspheres by using Thermal Process","volume":"205","author":"Lee","year":"2017","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_26","first-page":"e02754","article-title":"Shedding Light on the Cellular Uptake Mechanisms of Bioactive Glass Nanoparticles as Controlled Intracellular Delivery Platforms: A Review of the Recent Literature","volume":"15","author":"Boccaccini","year":"2025","journal-title":"Adv. Healthc. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.actbio.2010.07.028","article-title":"Liquid-liquid two-phase systems for the production of porous hydrogels and hydrogel microspheres for biomedical applications: A tutorial review","volume":"7","author":"Elbert","year":"2011","journal-title":"Acta Biomater."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.actbio.2016.06.033","article-title":"Bioactive glass-based materials with hierarchical porosity for medical applications: Review of recent advances","volume":"42","author":"Baino","year":"2016","journal-title":"Acta Biomater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1701444","DOI":"10.1002\/adhm.201701444","article-title":"Design Principles and Multifunctionality in Cell Encapsulation Systems for Tissue Regeneration","volume":"7","author":"Correia","year":"2018","journal-title":"Adv. Healthc. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Jin, C., Zhang, M., and Lin, J. (2023). Microcrystallization Effects in Borosilicate Bioactive Glasses: Controllable Release of Bioactive Elements and In Vitro Degradation Properties. Materials, 17.","DOI":"10.3390\/ma17010032"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3797","DOI":"10.1007\/s10904-022-02373-2","article-title":"Evaluation of In Vitro Bioactivity, Cytotoxicity, and Drug Release Behavior of Er2O3 and Tb2O3-Containing Bioactive Glass Particles and Nanofibers","volume":"32","author":"Rahman","year":"2022","journal-title":"J. Inorg. Organomet. Polym. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1527","DOI":"10.1039\/D3RA05529A","article-title":"Enhancing osteogenic differentiation of MC3T3-E1 cells during inflammation using UPPE\/beta-TCP\/TTC composites via the Wnt\/beta-catenin pathway","volume":"14","author":"Li","year":"2024","journal-title":"RSC Adv."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1","DOI":"10.33545\/26646862.2020.v2.i1a.13","article-title":"Hollow microspheres for drug delivery: A review","volume":"2","author":"Adesh","year":"2020","journal-title":"Int. J. Pharm. Res. Dev."},{"key":"ref_34","first-page":"72","article-title":"A Review Article on Floating Microballoons\/Hollow Microspheres Drug Delivery System","volume":"31","author":"Suthar","year":"2025","journal-title":"Int. J. Pharm. Pharm. Res."},{"key":"ref_35","first-page":"686","article-title":"Biomaterials targeting senescent cells for bone regeneration: State-of-the-art and future perspectives","volume":"54","author":"Wu","year":"2025","journal-title":"Bioact. Mater."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1007\/s13239-021-00534-x","article-title":"Enhanced Embolization Efficacy with the Embolic Microspheres Guided by the Aggregate Gradation Theory Through In Vitro and Simulation Evaluation","volume":"12","author":"Huang","year":"2021","journal-title":"Cardiovasc. Eng. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2056","DOI":"10.1039\/D5MA00057B","article-title":"Highly elastic polyvinyl alcohol embolic microspheres for effective transarterial embolization","volume":"6","author":"Liu","year":"2025","journal-title":"Mater. Adv."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Molinar-Diaz, J., Arjuna, A., Abrehart, N., McLellan, A., Harris, R., Islam, M.T., Alzaidi, A., Bradley, C.R., Gidman, C., and Prior, M.J.W. (2024). Development of Resorbable Phosphate-Based Glass Microspheres as MRI Contrast Media Agents. Molecules, 29.","DOI":"10.3390\/molecules29184296"},{"key":"ref_39","first-page":"221","article-title":"Microspheres: Preparation Methods, Advances, Applications, and Challenges in Drug Delivery","volume":"4","author":"Bhalala","year":"2025","journal-title":"Biomed. Mater. Dev."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Guo, L., Ping, J., Qin, J., Yang, M., Wu, X., You, M., You, F., and Peng, H. (2021). A Comprehensive Study of Drug Loading in Hollow Mesoporous Silica Nanoparticles: Impacting Factors and Loading Efficiency. Nanomaterials, 11.","DOI":"10.3390\/nano11051293"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"25480","DOI":"10.1039\/C8RA03943G","article-title":"Preparation of porous calcium phosphate microspheres with phosphate-containing molecules at room temperature for drug delivery and osteogenic differentiation","volume":"8","author":"Liu","year":"2018","journal-title":"RSC Adv."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"4270","DOI":"10.1021\/acsabm.4c00613","article-title":"Nanofibrous Microspheres: A Biomimetic Platform for Bone Tissue Regeneration","volume":"7","author":"Desai","year":"2024","journal-title":"ACS Appl. Bio Mater."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1007\/s12668-024-01640-5","article-title":"Overview of Nanofibres as Ideal Drug Delivery Systems for Pharmaceutical and Medicinal Applications","volume":"15","author":"Bashir","year":"2024","journal-title":"BioNanoScience"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.actbio.2017.05.020","article-title":"Carbon nanotube, graphene and boron nitride nanotube reinforced bioactive ceramics for bone repair","volume":"61","author":"Gao","year":"2017","journal-title":"Acta Biomater."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1632","DOI":"10.1016\/j.actbio.2013.07.003","article-title":"Micro- and nanofabrication of chitosan structures for regenerative engineering","volume":"10","author":"Jiang","year":"2014","journal-title":"Acta Biomater."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.actbio.2021.03.067","article-title":"Recent advances in PLGA-based biomaterials for bone tissue regeneration","volume":"127","author":"Jin","year":"2021","journal-title":"Acta Biomater."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.actbio.2018.09.052","article-title":"Mesoporous bioactive glasses: Promising platforms for antibacterial strategies","volume":"81","author":"Kargozar","year":"2018","journal-title":"Acta Biomater."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"2355","DOI":"10.1016\/j.actbio.2011.03.016","article-title":"Bioactive glass in tissue engineering","volume":"7","author":"Rahaman","year":"2011","journal-title":"Acta Biomater."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"e2001986","DOI":"10.1002\/adhm.202001986","article-title":"Multi-Dimensional Printing for Bone Tissue Engineering","volume":"10","author":"Qu","year":"2021","journal-title":"Adv. Healthc. Mater."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1268","DOI":"10.1002\/adhm.201400760","article-title":"Biomaterials for Bone Regenerative Engineering","volume":"4","author":"Yu","year":"2015","journal-title":"Adv. Healthc. Mater."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"5177","DOI":"10.1002\/adma.201101586","article-title":"Bioceramics: From bone regeneration to cancer nanomedicine","volume":"23","year":"2011","journal-title":"Adv. Mater."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"e2312964","DOI":"10.1002\/adma.202312964","article-title":"Bioactive Glass in Tissue Regeneration: Unveiling Recent Advances in Regenerative Strategies and Applications","volume":"37","author":"Zhu","year":"2025","journal-title":"Adv. Mater."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Almasri, D., and Dahman, Y. (2025). Bioactive Glass Preloaded with Antibiotics for Delivery of Long-Term Localized Drug Release Exhibiting Inherent Antimicrobial Activity. Appl. Sci., 15.","DOI":"10.20944\/preprints202504.1838.v1"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1016\/j.actbio.2008.10.018","article-title":"Composite fibrous biomaterials for tissue engineering obtained using a supercritical CO2 antisolvent process","volume":"5","author":"Domingo","year":"2009","journal-title":"Acta Biomater."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1700681","DOI":"10.1002\/adhm.201700681","article-title":"Fundamentals of Laser-Based Hydrogel Degradation and Applications in Cell and Tissue Engineering","volume":"6","author":"Pradhan","year":"2017","journal-title":"Adv. Healthc. Mater."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1143","DOI":"10.1002\/adma.201403354","article-title":"Nature-based nanocomposites for bone tissue engineering and regenerative medicine: A review","volume":"27","author":"Pina","year":"2015","journal-title":"Adv. Mater."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"212733","DOI":"10.1016\/j.bioadv.2022.212733","article-title":"Preparation and characterization of Pullulan-based nanocomposite scaffold incorporating Ag-Silica Janus particles for bone tissue engineering","volume":"135","author":"Moris","year":"2022","journal-title":"Biomater. Adv."},{"key":"ref_58","first-page":"1","article-title":"Immunomodulatory biomaterials and their application in therapies for chronic inflammation-related diseases","volume":"123","author":"Li","year":"2021","journal-title":"Acta Biomater."},{"key":"ref_59","doi-asserted-by":"crossref","unstructured":"Zhang, W., Zeng, X., Deng, X., Yang, F., Ma, X., and Gao, W. (2025). Smart biomaterials: As active immune modulators to shape pro-regenerative microenvironments. Front. Cell Dev. Biol., 13.","DOI":"10.3389\/fcell.2025.1669399"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.actbio.2018.04.026","article-title":"Piezoelectric materials as stimulatory biomedical materials and scaffolds for bone repair","volume":"73","author":"Tandon","year":"2018","journal-title":"Acta Biomater."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.actbio.2018.09.031","article-title":"Current state of fabrication technologies and materials for bone tissue engineering","volume":"80","author":"Wubneh","year":"2018","journal-title":"Acta Biomater."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"e2202766","DOI":"10.1002\/adhm.202202766","article-title":"Bone Tissue Engineering Scaffolds: Function of Multi-Material Hierarchically Structured Scaffolds","volume":"12","author":"Koushik","year":"2023","journal-title":"Adv. Healthc. Mater."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"e2302664","DOI":"10.1002\/adhm.202302664","article-title":"Advanced Synthetic Scaffolds Based on 1D Inorganic Micro-\/Nanomaterials for Bone Regeneration","volume":"13","author":"Zhang","year":"2024","journal-title":"Adv. Healthc. Mater."},{"key":"ref_64","first-page":"263","article-title":"Nanomaterial-assisted theranosis of bone diseases","volume":"24","author":"Zheng","year":"2023","journal-title":"Bioact. Mater."},{"key":"ref_65","doi-asserted-by":"crossref","unstructured":"Zaszczynska, A., Zabielski, K., Gradys, A., Kowalczyk, T., and Sajkiewicz, P. (2024). Piezoelectric Scaffolds as Smart Materials for Bone Tissue Engineering. Polymers, 16.","DOI":"10.3390\/polym16192797"},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.actbio.2021.07.028","article-title":"Porous nerve guidance conduits reinforced with braided composite structures of silk\/magnesium filaments for peripheral nerve repair","volume":"134","author":"Zhang","year":"2021","journal-title":"Acta Biomater."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1007\/s00289-025-06102-w","article-title":"Tissue regeneration and controlled drug delivery mediated by silk fibroin","volume":"83","author":"Allela","year":"2025","journal-title":"Polym. Bull."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"e1800465","DOI":"10.1002\/adhm.201800465","article-title":"The Biomedical Use of Silk: Past, Present, Future","volume":"8","author":"Holland","year":"2019","journal-title":"Adv. Healthc. Mater."},{"key":"ref_69","doi-asserted-by":"crossref","unstructured":"Wani, S.U.D., Zargar, M.I., Masoodi, M.H., Alshehri, S., Alam, P., Ghoneim, M.M., Alshlowi, A., Shivakumar, H.G., Ali, M., and Shakeel, F. (2022). Silk Fibroin as an Efficient Biomaterial for Drug Delivery, Gene Therapy, and Wound Healing. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms232214421"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"e2312474","DOI":"10.1002\/adma.202312474","article-title":"Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy","volume":"36","author":"Ghasemlou","year":"2024","journal-title":"Adv. Mater."},{"key":"ref_71","doi-asserted-by":"crossref","unstructured":"Tran, V., Nguyen, N., Renkes, S., Nguyen, K.T., Nguyen, T., and Alexandrakis, G. (2025). Current and Near-Future Technologies to Quantify Nanoparticle Therapeutic Loading Efficiency and Surface Coating Efficiency with Targeted Moieties. Bioengineering, 12.","DOI":"10.3390\/bioengineering12040362"},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"1504","DOI":"10.1002\/adma.201104763","article-title":"Mesoporous silica nanoparticles: Synthesis, biocompatibility and drug delivery","volume":"24","author":"Tang","year":"2012","journal-title":"Adv. Mater."},{"key":"ref_73","doi-asserted-by":"crossref","unstructured":"Fatima, R., Katiyar, P., and Kushwaha, K. (2025). Recent advances in mesoporous silica nanoparticle: Synthesis, drug loading, release mechanisms, and diverse applications. Front. Nanotechnol., 7.","DOI":"10.3389\/fnano.2025.1564188"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"e2306035","DOI":"10.1002\/advs.202306035","article-title":"Layered Double Hydroxides: Recent Progress and Promising Perspectives Toward Biomedical Applications","volume":"11","author":"Li","year":"2024","journal-title":"Adv. Sci."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1186\/s44301-025-00017-1","article-title":"Layered double hydroxides based nanomaterials: Recent advances in drug delivery and biomedical applications","volume":"1","author":"Shivakumar","year":"2025","journal-title":"Health Nanotechnol."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"298","DOI":"10.3390\/pharmaceutics6020298","article-title":"Layered double hydroxide-based nanocarriers for drug delivery","volume":"6","author":"Bi","year":"2014","journal-title":"Pharmaceutics"},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"015014","DOI":"10.1088\/1758-5082\/5\/1\/015014","article-title":"Fabrication of porous polyvinyl alcohol scaffold for bone tissue engineering via selective laser sintering","volume":"5","author":"Shuai","year":"2013","journal-title":"Biofabrication"},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"123186","DOI":"10.1016\/j.biomaterials.2025.123186","article-title":"Hierarchical interconnected porous scaffolds with regulated interfacial nanotopography exhibit antimicrobial, alleviate inflammation, neovascularization, and tissue integration for bone regeneration","volume":"318","author":"Shirun","year":"2025","journal-title":"Biomaterials"},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"2","DOI":"10.4172\/2090-5025.S1-009","article-title":"Fabrication, Characterization and Drug Release of Ciprofloxacin Loaded Porous Polyvinyl Alcohol\/Bioactive Glass Scaffold for Controlled Drug Delivery","volume":"3","author":"Mabrouk","year":"2013","journal-title":"Bioceram. Dev. Appl."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.nano.2009.06.004","article-title":"Porous-wall hollow glass microspheres as novel potential nanocarriers for biomedical applications","volume":"6","author":"Li","year":"2010","journal-title":"Nanomed. Nanotechnol. Biol. Med."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"1","DOI":"10.4103\/2229-5186.129327","article-title":"Hollow microspheres as a drug carrier: An overview of fabrication and in vivocharacterization techniques","volume":"5","author":"Suresh","year":"2014","journal-title":"Chron. Young Sci."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1146\/annurev-bioeng-071516-044712","article-title":"Microsphere-Based Scaffolds in Regenerative Engineering","volume":"19","author":"Gupta","year":"2017","journal-title":"Annu. Rev. Biomed. Eng."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"213958","DOI":"10.1016\/j.bioadv.2024.213958","article-title":"Novel multi-functional microsphere scaffold with shape memory function for bone regeneration","volume":"163","author":"Hu","year":"2024","journal-title":"Biomater. Adv."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"012005","DOI":"10.1088\/1742-6596\/2243\/1\/012005","article-title":"Developing Highly Porous Glass Microspheres via a Single-Stage Flame Spheroidisation Process","volume":"2243","author":"Nuzulia","year":"2022","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"100315","DOI":"10.1016\/j.mtadv.2022.100315","article-title":"Microspheres in bone regeneration: Fabrication, properties and applications","volume":"16","author":"Cai","year":"2022","journal-title":"Mater. Today Adv."},{"key":"ref_86","doi-asserted-by":"crossref","unstructured":"Feng, Z., Su, X., Wang, T., Sun, X., Yang, H., and Guo, S. (2023). The Role of Microsphere Structures in Bottom-Up Bone Tissue Engineering. Pharmaceutics, 15.","DOI":"10.3390\/pharmaceutics15020321"},{"key":"ref_87","unstructured":"Toshiya Matsubara, C., Masaharu Tanaka, C., Makoto Kusaka, C., Kenji Yamada, C., and Yasumasa Nakao, K. (2002). Hollow Glass Microspheres and Process for Their Production. (US20020004111A1), U.S. Patent."},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"012010","DOI":"10.1088\/1755-1315\/821\/1\/012010","article-title":"Research on the Preparation and Performance of a New Type of Hollow Glass Microspheres","volume":"821","author":"Wang","year":"2011","journal-title":"IOP Conf. Ser. Earth Environ. Sci."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1177\/0731684419877568","article-title":"Compressive properties of co-continuous hollow glass microsphere\/epoxy resin syntactic foams prepared using resin transfer moulding","volume":"39","author":"Ding","year":"2019","journal-title":"J. Reinf. Plast. Compos."},{"key":"ref_90","first-page":"1380","article-title":"A Comprehensive Review of Bioactive Glasses: Synthesis, Characterization, and Applications in Regenerative Medicine","volume":"4","author":"Madival","year":"2025","journal-title":"Biomed. Mater. Dev."},{"key":"ref_91","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1023\/A:1023846418115","article-title":"Structure of the BaO\u2014Al2O3\u2014SiO2 System (A Review)","volume":"60","author":"Shabanova","year":"2003","journal-title":"Glass Ceram."},{"key":"ref_92","doi-asserted-by":"crossref","first-page":"1679","DOI":"10.1016\/j.jnoncrysol.2009.06.036","article-title":"Thermodynamic modeling of the Al2O3\u2013B2O3\u2013SiO2 system","volume":"355","author":"Swamy","year":"2009","journal-title":"J. Non-Cryst. Solids"},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"106060","DOI":"10.1016\/j.mtcomm.2023.106060","article-title":"On the compressive properties of aluminum and magnesium syntactic foams: Experiment and simulation","volume":"35","author":"Kubelka","year":"2023","journal-title":"Mater. Today Comm."},{"key":"ref_94","first-page":"1","article-title":"A Review on the Mechanical Properties and Environmental Impact of Hollow Glass Microsphere Epoxy Composites","volume":"9","author":"Bhatia","year":"2018","journal-title":"IIOABJ"},{"key":"ref_95","first-page":"6","article-title":"The structure formation in polymer composites with hollow glass microspheres","volume":"11","author":"Trofimov","year":"2012","journal-title":"Int. Polym. Sci. Technol."},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"4550","DOI":"10.1007\/s10854-021-07646-z","article-title":"Investigation of PTFE-based ultra-low dielectric constant composite substrates with hollow silica ceramics","volume":"33","author":"Wang","year":"2022","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_97","unstructured":"Ali, M.H., Rubel, R.I., Yusuf, S.S., and Siddique, M.A. (2019, January 6\u20137). A review on syntactic foams processing, preparation and applications. Proceedings of the International Conference on Mechanical Engineering and Renewable Energy 2019, Chittagong, Bangladesh."},{"key":"ref_98","doi-asserted-by":"crossref","unstructured":"Galvagnini, F., Fredi, G., Dorigato, A., Fambri, L., and Pegoretti, A. (2021). Mechanical Behaviour of Multifunctional Epoxy\/Hollow Glass Microspheres\/Paraffin Microcapsules Syntactic Foams for Thermal Management. Polymers, 13.","DOI":"10.3390\/polym13172896"},{"key":"ref_99","doi-asserted-by":"crossref","first-page":"012064","DOI":"10.1088\/1742-6596\/991\/1\/012064","article-title":"Analysis of syntactic foam\u2014GFRP sandwich composites for flexural loads","volume":"991","author":"Daniel","year":"2018","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_100","doi-asserted-by":"crossref","first-page":"012080","DOI":"10.1088\/1742-6596\/1240\/1\/012080","article-title":"Mechanical and wear properties of epoxy matrix composite reinforced with varying ratios of solid glass microspheres","volume":"1240","author":"Bhatia","year":"2019","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_101","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1515\/secm-2021-0011","article-title":"Processing of Hollow Glass Microspheres (HGM) filled Epoxy Syntactic Foam Composites with improved Structural Characteristics","volume":"28","author":"Afolabi","year":"2021","journal-title":"Sci. Eng. Compos. Mater."},{"key":"ref_102","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/S1044-5803(99)00039-X","article-title":"Correlation of Processing Methodology to the Physical and Mechanical Properties of Syntactic Foams with and Without Fibres","volume":"43","author":"Gupta","year":"1999","journal-title":"Mater. Charact."},{"key":"ref_103","first-page":"59","article-title":"Effects of Water Absorption on Mechanical Properties of Glass Microballoons\/Vinyl Ester Syntactic Foams","volume":"8","author":"Zulzamri","year":"2018","journal-title":"Res. Rev. Mater. Sci. Chem."},{"key":"ref_104","doi-asserted-by":"crossref","first-page":"732","DOI":"10.1177\/073168440001900904","article-title":"Comparison of compressive properties of Fibre-Free and Fibre-Bearing Syntactic Foams","volume":"19","author":"Karthikeyan","year":"2000","journal-title":"J. Reinf. Plast. Compos."},{"key":"ref_105","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.mee.2014.06.017","article-title":"Preparation and characterization of hollow glass microspheres (HGMs) for hydrogen storage using urea as a blowing agent","volume":"126","author":"Dalai","year":"2014","journal-title":"Microelect. Eng."},{"key":"ref_106","doi-asserted-by":"crossref","unstructured":"Tassaw, D.F., Barburski, M., and Kassie, B.B. (2025). The Role of Hollow Glass Microspheres as Functional Fillers in Fibre-Reinforced Polymer Composites: A Review. Materials, 18.","DOI":"10.3390\/ma18214974"},{"key":"ref_107","doi-asserted-by":"crossref","unstructured":"Gomez, S.G., Irigoyen, A., Gonzalez, S., Estala-Rodriguez, K., Shafirovich, E., Hassan, S., Zaman, S., and Lin, Y. (2023). Fabrication and Characterization of Hollow Polysiloxane Microsphere Polymer Matrix Composites with Improved Energy Absorption. J. Compos. Sci., 7.","DOI":"10.3390\/jcs7030098"},{"key":"ref_108","doi-asserted-by":"crossref","unstructured":"Afolabi, O.A., Kanny, K., and Mohan, T.P. (2022). Analysis of Particle Variation Effect on Flexural Properties of Hollow Glass Microsphere Filled Epoxy Matrix Syntactic Foam Composites. Polymers, 14.","DOI":"10.20944\/preprints202211.0012.v1"},{"key":"ref_109","doi-asserted-by":"crossref","first-page":"126625","DOI":"10.1016\/j.matlet.2019.126625","article-title":"Porous Bioactive Glass Microspheres Prepared by Flame Synthesis Process","volume":"256","author":"Kraxner","year":"2019","journal-title":"Mater. Lett."},{"key":"ref_110","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1007\/s10717-023-00570-0","article-title":"Properties of Hollow Glass Microspheres Obtained in a Propane-Air Torch","volume":"80","author":"Shekhovtsov","year":"2023","journal-title":"Glass Ceram."},{"key":"ref_111","doi-asserted-by":"crossref","first-page":"32896","DOI":"10.1021\/acsami.7b09884","article-title":"Flexible Microsphere-Embedded Film for Microsphere-Enhanced Raman Spectroscopy","volume":"9","author":"Xing","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_112","doi-asserted-by":"crossref","first-page":"3467","DOI":"10.1557\/s43578-023-01065-y","article-title":"Effect of hollow glass microsphere on the processing and flame retardancy of intumescent flame-retardant polypropylene composites prepared by selective laser sintering","volume":"38","author":"Zhao","year":"2023","journal-title":"J. Mater. Res."},{"key":"ref_113","unstructured":"U.S. Food and Drug Administration (2023). Use of International Standard ISO 10993-1, \"Biological Evaluation of Medical Devices\u2014Part 1: Evaluation and Testing Within a Risk Management Process\", Guidance for Industry and Food and Drug Administration Staff, U.S. Food and Drug Administration (FDA)."},{"key":"ref_114","doi-asserted-by":"crossref","first-page":"172999","DOI":"10.1016\/j.jallcom.2023.172999","article-title":"Tailored nanoparticles for magnetic hyperthermia: Highly stable aqueous dispersion of Mn-substituted magnetite superparamagnetic nanoparticles by double surfactant coating for improved heating efficiency","volume":"976","author":"Singh","year":"2024","journal-title":"J. Alloys Compd."},{"key":"ref_115","doi-asserted-by":"crossref","unstructured":"Petru, A.E., Iacovita, C., Fizesan, I., Dudric, R., Crestin, I.V., Lucaciu, C.M., Loghin, F., and Kiss, B. (2025). Evaluating Manganese-Doped Magnetic Nanoflowers for Biocompatibility and In Vitro Magnetic Hyperthermia Efficacy. Pharmaceutics, 17.","DOI":"10.3390\/pharmaceutics17030384"}],"container-title":["Pharmaceuticals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8247\/19\/8\/1183\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T11:54:52Z","timestamp":1785239692000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8247\/19\/8\/1183"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,28]]},"references-count":115,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["ph19081183"],"URL":"https:\/\/doi.org\/10.3390\/ph19081183","relation":{},"ISSN":["1424-8247"],"issn-type":[{"value":"1424-8247","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,28]]}}}