{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T22:42:48Z","timestamp":1785451368967,"version":"3.56.0"},"reference-count":28,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2021,11,24]],"date-time":"2021-11-24T00:00:00Z","timestamp":1637712000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Health Holland","award":["LSHI20003"],"award-info":[{"award-number":["LSHI20003"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Systemic sclerosis (SSc) is a rare, severe, auto-immune disease characterized by inflammation, vasculopathy and fibrosis. Activated (myo)fibroblasts are crucial drivers of this fibrosis. By exploiting their expression of fibroblast activation protein (FAP) to perform targeted photodynamic therapy (tPDT), we can locoregionally deplete these pathogenic cells. In this study, we explored the use of FAP-tPDT in primary skin fibroblasts from SSc patients, both in 2D and 3D cultures. Method: The FAP targeting antibody 28H1 was conjugated with the photosensitizer IRDye700DX. Primary skin fibroblasts were obtained from lesional skin biopsies of SSc patients via spontaneous outgrowth and subsequently cultured on plastic or collagen type I. For 2D FAP-tPDT, cells were incubated in buffer with or without the antibody-photosensitizer construct, washed after 4 h and exposed to \u03bb = 689 nm light. Cell viability was measured using CellTiter Glo\u00ae\u00ae. For 3D FAP-tPDT, cells were seeded in collagen plugs and underwent the same treatment procedure. Contraction of the plugs was followed over time to determine myofibroblast activity. Results: FAP-tPDT resulted in antibody-dose dependent cytotoxicity in primary skin fibroblasts upon light exposure. Cells not exposed to light or incubated with an irrelevant antibody-photosensitizer construct did not show this response. FAP-tPDT fully prevented contraction of collagen plugs seeded with primary SSc fibroblasts. Even incubation with a very low dose of antibody (0.4 nM) inhibited contraction in 2 out of 3 donors. Conclusions: Here we have shown, for the first time, the potential of FAP-tPDT for the treatment of fibrosis in SSc skin.<\/jats:p>","DOI":"10.3390\/ijms222312681","type":"journal-article","created":{"date-parts":[[2021,11,30]],"date-time":"2021-11-30T04:48:37Z","timestamp":1638247717000},"page":"12681","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Fibroblast Activation Protein Targeted Photodynamic Therapy Selectively Kills Activated Skin Fibroblasts from Systemic Sclerosis Patients and Prevents Tissue Contraction"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9292-0693","authenticated-orcid":false,"given":"Daphne N.","family":"Dorst","sequence":"first","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5473-4884","authenticated-orcid":false,"given":"Arjan P. M.","family":"van Caam","sequence":"additional","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elly L.","family":"Vitters","sequence":"additional","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Birgitte","family":"Walgreen","sequence":"additional","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monique M. A.","family":"Helsen","sequence":"additional","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7594-7280","authenticated-orcid":false,"given":"Christian","family":"Klein","sequence":"additional","affiliation":[{"name":"Roche Pharma Research and Early Development, Roche Innovation Center Zurich, 8952 Schlieren, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shreya","family":"Gudi","sequence":"additional","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tirza","family":"Wubs","sequence":"additional","affiliation":[{"name":"Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jyoti","family":"Kumari","sequence":"additional","affiliation":[{"name":"Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Madelon C.","family":"Vonk","sequence":"additional","affiliation":[{"name":"Department of Rheumatology, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter M.","family":"van der Kraan","sequence":"additional","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marije I.","family":"Koenders","sequence":"additional","affiliation":[{"name":"Department of Experimental Rheumatology, Radboud University Medical Centre, Daphne Dorst, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1327","DOI":"10.1136\/annrheumdis-2016-209909","article-title":"Update of EULAR recommendations for the treatment of systemic sclerosis","volume":"76","author":"Fransen","year":"2017","journal-title":"Ann. Rheum. 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