{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T05:14:17Z","timestamp":1769836457096,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2021,10,21]],"date-time":"2021-10-21T00:00:00Z","timestamp":1634774400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Norte Portugal Regional Operational Programme","award":["NORTE-01-0145-FEDER-000012"],"award-info":[{"award-number":["NORTE-01-0145-FEDER-000012"]}]},{"name":"PTDC\/BBB-NAN\/3249\/2014","award":["NORTE-08-5369-FSE-000007"],"award-info":[{"award-number":["NORTE-08-5369-FSE-000007"]}]},{"name":"FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI)","award":["FEDER"],"award-info":[{"award-number":["FEDER"]}]},{"name":"Portuguese funds through FCT - Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia\/ Minist\u00e9rio da Ci\u00eancia, Tecnologia e Ensino Superior in the framework of the project &quot;Institute for Research and Inno-vation in Health Sciences&quot;","award":["POCI-01-0145-FEDER-007274"],"award-info":[{"award-number":["POCI-01-0145-FEDER-007274"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>Background: Biological molecules such as therapeutic proteins and peptides have provided ample opportunities for further improvements in health and wellbeing. However, such biomacromolecules face stability challenges regarding premature processing and digestion, whenever any enteric delivery route is considered. Hence, oral guar films entrapping peptide-containing chitosan microparticles have been developed as a new delivery system to carry and protect therapeutic relaxing peptides. Results: The composite films were characterized regarding physicochemical properties using FTIR as well as peptide encapsulation efficiency, cytotoxicity, and peptide permeability through buccal and intestinal cell-based models. The composite films with 0.18% (w\/w) of peptide demonstrated ca. 0.63% of peptide loading efficiency into the chitosan microparticles and to be safe for buccal and intestinal epithelial cells up to 24 h of contact. The permeability assays through TR146 cells to mimic buccal mucosa epithelium and Caco-2\/HT29-MTX to mimic duodenum conditions showed that the incorporation of peptide chitosan microparticles into guar-gum oral films offered a faster permeability, when compared with the free peptide and peptide-chitosan-microparticles-loaded chitosan. Conclusion: This study suggests that peptide-loaded chitosan microparticles into guar-gum oral films might be a promising carrier for enhancement of the buccal and intestinal absorption of a relaxing peptide.<\/jats:p>","DOI":"10.3390\/app11219849","type":"journal-article","created":{"date-parts":[[2021,10,21]],"date-time":"2021-10-21T14:37:48Z","timestamp":1634827068000},"page":"9849","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Preparation, Characterization and Evaluation of Guar Films Impregnated with Relaxing Peptide Loaded into Chitosan Microparticles"],"prefix":"10.3390","volume":"11","author":[{"given":"Patr\u00edcia","family":"Batista","sequence":"first","affiliation":[{"name":"Research Centre for Human Development, HNL\/CEDH\u2014Human Neurobehavioral Laboratory, Universidade Cat\u00f3lica Portuguesa, Rua de Diogo Botelho 1327, 4169-005 Porto, Portugal"},{"name":"CBQF-Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]},{"given":"Pedro M.","family":"Castro","sequence":"additional","affiliation":[{"name":"CBQF-Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]},{"given":"Ana Raquel","family":"Madureira","sequence":"additional","affiliation":[{"name":"CBQF-Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5763-7553","authenticated-orcid":false,"given":"Bruno","family":"Sarmento","sequence":"additional","affiliation":[{"name":"i3S-Instituto de Investiga\u00e7\u00e3o e Inova\u00e7\u00e3o em Sa\u00fade, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal"},{"name":"INEB-Instituto Nacional de Engenharia Biom\u00e9dica, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal"},{"name":"CESPU, Instituto de Investiga\u00e7\u00e3o e Forma\u00e7\u00e3o Avan\u00e7ada em Ci\u00eancias e Tecnologias da Sa\u00fade, Rua Central de Gandra 1317, 4585-116 Gandra, Portugal"}]},{"given":"Manuela","family":"Pintado","sequence":"additional","affiliation":[{"name":"CBQF-Centro de Biotecnologia e Qu\u00edmica Fina\u2014Laborat\u00f3rio Associado, Escola Superior de Biotecnologia, Universidade Cat\u00f3lica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1016\/j.jconrel.2015.05.258","article-title":"Oral films as breakthrough tools for oral delivery of proteins\/peptides","volume":"211","author":"Castro","year":"2015","journal-title":"J. Control. Release"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3764","DOI":"10.1002\/jps.24142","article-title":"Mucoadhesive films containing chitosan-coated nanoparticles: A new strategy for buccal curcumin release","volume":"103","author":"Mazzarino","year":"2014","journal-title":"J. Pharm. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.peptides.2018.01.002","article-title":"Recent insights in the use of nanocarriers for the oral delivery of bioactive proteins and peptides","volume":"101","author":"Batista","year":"2018","journal-title":"Peptides"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1016\/j.carbpol.2018.04.032","article-title":"Incorporation of beads into oral films for buccal and oral delivery of bioactive molecules","volume":"194","author":"Castro","year":"2018","journal-title":"Carbohydr. Polym."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.ijpharm.2012.02.035","article-title":"Development and characterisation of chitosan films impregnated with insulin loaded PEG-b-PLA nanoparticles (NPs): A potential approach for buccal delivery of macromolecules","volume":"428","author":"Giovino","year":"2012","journal-title":"Int. J. Pharm."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.ijbiomac.2011.04.022","article-title":"Prospective of guar gum and its derivatives as controlled drug delivery systems","volume":"49","author":"Prabaharan","year":"2011","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_7","unstructured":"Seeli, D.S., Prabaharan, M., Thakur, V., and Thakur, M. (2016). Guar gum and its derivatives: Versatile materials for controlled drug delivery. Handbook of Sustainable Polymers, CRC Press."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.cis.2018.02.002","article-title":"Encapsulation, protection, and delivery of bioactive proteins and peptides using nanoparticle and microparticle systems: A review","volume":"253","author":"McClements","year":"2018","journal-title":"Adv. Colloid Interface Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.drudis.2014.10.003","article-title":"Peptide therapeutics: Current status and future directions","volume":"20","author":"Fosgerau","year":"2015","journal-title":"Drug Discov. Today"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.jff.2017.12.063","article-title":"Whey protein hydrolysates as a source of bioactive peptides for functional foods\u2013Biotechnological facilitation of industrial scale-up","volume":"42","author":"Dullius","year":"2018","journal-title":"J. Funct. Foods"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1016\/j.jconrel.2014.09.003","article-title":"Microencapsulation of protein drugs for drug delivery: Strategy, preparation, and applications","volume":"193","author":"Ma","year":"2014","journal-title":"J. Control. Release"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.peptides.2015.07.013","article-title":"Bioactive peptides derived from natural proteins with respect to diversity of their receptors and physiological effects","volume":"72","author":"Yoshikawa","year":"2015","journal-title":"Peptides"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1312","DOI":"10.1208\/s12249-015-0466-y","article-title":"Development and evaluation of biodegradable chitosan films of metronidazole and levofloxacin for the management of periodontitis","volume":"17","author":"Khan","year":"2016","journal-title":"AAPS PharmSciTech"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1084","DOI":"10.1208\/s12249-016-0677-x","article-title":"Effect of formulation and process parameters on chitosan microparticles prepared by an emulsion crosslinking technique","volume":"18","author":"Rodriguez","year":"2017","journal-title":"AAPS PharmSciTech"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"84","DOI":"10.4103\/SDJ.SDJ_41_20","article-title":"The effect difference of chitosan nanoparticles, chitosan microparticles, and casein phosphopeptide\u2013 amorphous calcium phosphate in reducing enamel demineralization","volume":"4","author":"Effendi","year":"2020","journal-title":"Sci. Dent. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1208\/s12249-020-01786-x","article-title":"Antimicrobial activity of schinopsis brasiliensis engler extract-loaded chitosan microparticles in oral infectious disease","volume":"21","author":"Duarte","year":"2020","journal-title":"AAPS PharmSciTech"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1002\/(SICI)1097-4628(19970103)63:1<125::AID-APP13>3.0.CO;2-4","article-title":"Novel hydrophilic chitosan-polyethylene oxide nanoparticles as protein carriers","volume":"63","author":"Calvo","year":"1997","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"9199","DOI":"10.1016\/j.biomaterials.2014.07.026","article-title":"The impact of nanoparticles on the mucosal translocation and transport of GLP-1 across the intestinal epithelium","volume":"35","author":"Shrestha","year":"2014","journal-title":"Biomaterials"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/j.msec.2017.02.173","article-title":"Optimization of two biopolymer-based oral films for the delivery of bioactive molecules","volume":"76","author":"Castro","year":"2017","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1016\/0378-5173(96)04640-6","article-title":"TR146 cells as a model for human buccal epithelium: II. Optimisation and use of a cellular sensitivity MTS\/PMS assay","volume":"141","author":"Jacobsen","year":"1996","journal-title":"Int. J. Pharm."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/S0378-5173(99)00368-3","article-title":"TR146 cells grown on filters as a model of human buccal epithelium: IV. Permeability of water, mannitol, testosterone and \u03b2-adrenoceptor antagonists. Comparison to human, monkey and porcine buccal mucosa","volume":"194","author":"Nielsen","year":"2000","journal-title":"Int. J. Pharm."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1023\/A:1014220832384","article-title":"The potential of chitosan in enhancing peptide and protein absorption across the TR146 cell culture model\u2014An in vitro model of the buccal epithelium","volume":"19","author":"Portero","year":"2002","journal-title":"Pharm. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1410","DOI":"10.1039\/c3fo60180c","article-title":"Utilization of solid lipid nanoparticles for enhanced delivery of curcumin in cocultures of HT29-MTX and Caco-2 cells","volume":"4","author":"Guri","year":"2013","journal-title":"Food Funct."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Nixon, A.E. (2014). Therapeutic Peptides: Methods and Protocols, Springer.","DOI":"10.1007\/978-1-62703-673-3"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1016\/j.jpba.2017.11.069","article-title":"Mixture design applied in compatibility studies of catechin and lipid compounds","volume":"149","author":"Gratieri","year":"2018","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"680","DOI":"10.3109\/09637486.2015.1077792","article-title":"Optimization of Caco-2 and HT29 co-culture in vitro cell models for permeability studies","volume":"66","author":"Pan","year":"2015","journal-title":"Int. J. Food Sci. Nutr."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1704463","DOI":"10.1002\/adma.201704463","article-title":"Nanoparticle\u2013cell interaction: A cell mechanics perspective","volume":"30","author":"Septiadi","year":"2018","journal-title":"Adv. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.biopha.2014.12.047","article-title":"Didanosine-loaded chitosan microspheres optimized by surface-response methodology: A modified \u201cMaximum Likelihood Classification\u201d approach formulation for reverse transcriptase inhibitors","volume":"70","author":"Severino","year":"2015","journal-title":"Biomed. Pharmacother."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2940","DOI":"10.1002\/app.12386","article-title":"Synthesis and characterization of modified chitosan microspheres: Effect of the grafting ratio on the controlled release of nifedipine through microspheres","volume":"89","author":"Kumbar","year":"2003","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1016\/j.colsurfb.2014.04.024","article-title":"Development and characterization of GRGDSPC-modified poly (lactide-co-glycolide acid) porous microspheres incorporated with protein-loaded chitosan microspheres for bone tissue engineering","volume":"122","author":"Tao","year":"2014","journal-title":"Colloids Surf. B Biointerfaces"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Yu, T., Zhao, S., Li, Z., Wang, Y., Xu, B., Fang, D., Wang, F., Zhang, Z., He, L., and Song, X. (2016). Enhanced and extended anti-hypertensive effect of VP5 nanoparticles. Int. J. Mol. Sci., 17.","DOI":"10.3390\/ijms17121977"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"117","DOI":"10.2147\/nano.2006.1.2.117","article-title":"Chitosan nanoparticles for oral drug and gene delivery","volume":"1","author":"Bowman","year":"2006","journal-title":"Int. J. Nanomed."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1016\/j.ijbiomac.2017.03.163","article-title":"Properties of gelatin-based films incorporated with chitosan-coated microparticles charged with rutin","volume":"101","author":"Dammak","year":"2017","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1016\/j.carbpol.2015.04.020","article-title":"Fabrication of chitosan microspheres using vanillin\/TPP dual crosslinkers for protein antigens encapsulation","volume":"128","author":"Walke","year":"2015","journal-title":"Carbohydr. Polym."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/S0378-5173(02)00486-6","article-title":"Bioadhesive polysaccharide in protein delivery system: Chitosan nanoparticles improve the intestinal absorption of insulin in vivo","volume":"249","author":"Pan","year":"2002","journal-title":"Int. J. Pharm."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"3054","DOI":"10.1021\/bm0703923","article-title":"Oral bioavailability of insulin contained in polysaccharide nanoparticles","volume":"8","author":"Sarmento","year":"2007","journal-title":"Biomacromolecules"},{"key":"ref_37","first-page":"2127","article-title":"Nanolayer encapsulation of insulin-chitosan complexes improves efficiency of oral insulin delivery","volume":"9","author":"Song","year":"2014","journal-title":"Int. J. Nanomed."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2461","DOI":"10.1021\/bm0496211","article-title":"Monodisperse chitosan nanoparticles for mucosal drug delivery","volume":"5","author":"Zhang","year":"2004","journal-title":"Biomacromolecules"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1016\/j.jfda.2014.10.008","article-title":"Impact of chitosan composites and chitosan nanoparticle composites on various drug delivery systems: A review","volume":"23","author":"Elgadir","year":"2015","journal-title":"J. Food Drug Anal."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1003","DOI":"10.1016\/j.bmcl.2016.12.072","article-title":"Chitosan cross-linked with poly (ethylene glycol) dialdehyde via reductive amination as effective controlled release carriers for oral protein drug delivery","volume":"27","author":"Jing","year":"2017","journal-title":"Bioorganic Med. Chem. Lett."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1016\/j.biomaterials.2016.06.059","article-title":"ZOT-derived peptide and chitosan functionalized nanocarrier for oral delivery of protein drug","volume":"103","author":"Lee","year":"2016","journal-title":"Biomaterials"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3770","DOI":"10.1208\/s12249-018-1190-1","article-title":"Preparation and characterization of an oral vaccine formulation using electrosprayed chitosan microparticles","volume":"19","author":"Moreno","year":"2018","journal-title":"Aaps Pharmscitech"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1016\/j.foodhyd.2019.03.042","article-title":"Chitosan-coated zein nanoparticles for oral delivery of resveratrol: Formation, characterization, stability, mucoadhesive properties and antioxidant activity","volume":"94","author":"Pauluk","year":"2019","journal-title":"Food Hydrocoll."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1016\/j.ijpharm.2014.12.032","article-title":"Ink-jet printing versus solvent casting to prepare oral films: Effect on mechanical properties and physical stability","volume":"494","author":"Buanz","year":"2015","journal-title":"Int. J. Pharm."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"180","DOI":"10.3109\/03639040903468811","article-title":"Delayed release film coating applications on oral solid dosage forms of proton pump inhibitors: Case studies","volume":"36","author":"Missaghi","year":"2010","journal-title":"Drug Dev. Ind. Pharm."}],"container-title":["Applied Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3417\/11\/21\/9849\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:20:23Z","timestamp":1760167223000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3417\/11\/21\/9849"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,10,21]]},"references-count":45,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["app11219849"],"URL":"https:\/\/doi.org\/10.3390\/app11219849","relation":{},"ISSN":["2076-3417"],"issn-type":[{"value":"2076-3417","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,10,21]]}}}