EC Orthopaedics

Adhesive hydrogels are being investigated as scaffolds capable of remaining within focal chondral defects while supporting cellular retention and matrix deposition. This narrative critical appraisal examines the preclinical evidence reported by Karami and colleagues for phosphoserine-functionalized, photocurable hydrogels and considers whether those findings justify office-based intra-articular use. The source study combined mechanical testing, implantation into surgically created caprine cartilage defects, histology, and in-vitro culture of bovine chondrocytes. Its results support local retention and tissue-interface integration after direct placement followed by 405-nm photopolymerization. They do not, however, establish efficacy after unguided or image-guided intra- articular injection, demonstrate clinical benefit in humans, or validate commercial products not chemically shown to be equivalent to the tested MePHa and MePGa formulations. The evidence should therefore be interpreted as an early device-level proof of concept rather than as confirmation of a routine injectable treatment. Translation will require complete material characterization, dose and curing validation, biodistribution studies, standardized histological scoring, adequately powered animal comparisons, toxicology, and prospective human trials. Adhesive hydrogel technology is scientifically promising, but claims of superior clinical efficacy or practical in-office applicability remain premature.

Keywords: Adhesive Hydrogel; Cartilage Repair; Photopolymerization; Translational Medicine; Preclinical Evidence; Chondral Defect

1. Karami P., et al. “An adhesive hydrogel technology for enhanced cartilage repair: a preliminary proof of concept”. Gels10 (2024): 657.
2. Makris EA., et al. “Repair techniques and tissue engineering for articular cartilage”. Nature Reviews Rheumatology 11 (2015): 21-34.
3. Cong B., et al. “Current and innovative therapies for articular cartilage repair and regeneration”. Therapeutics and Clinical Risk Management (2023): 485-502.
4. Brittberg M. “Clinical articular cartilage repair - an updated review”. Annals of Joint 3 (2018): 94.
5. Haleem AM and Chu CR. “Advances in tissue engineering techniques for articular cartilage repair”. Operative Techniques in Orthopaedics 2 (2010): 76-89.
6. Khan IM., et al. “Cartilage integration: evaluation of the reasons for integration failure during cartilage repair”. European Cells and Materials 16 (2008): 26-39.
7. Teng L., et al. “Supramolecular and dynamic covalent hydrogel scaffolds: from gelation chemistry to enhanced cell retention and cartilage regeneration”. Journal of Materials Chemistry B 43 (2019): 6705-6736.
8. Sánchez-Téllez DA., et al. “Hydrogels for cartilage regeneration, from polysaccharides to hybrids”. Polymers 12 (2017): 671.
9. Karami P., et al. “Cartilage repair: promise of adhesive orthopedic hydrogels”. International Journal of Molecular Sciences18 (2024): 9984.
10. Karami P., et al. “A guide to preclinical evaluation of hydrogel-based devices for the treatment of cartilage lesions”. Acta Biomaterialia 158 (2023): 12-31.
11. Tibbitt MW and Anseth KS. “Hydrogels as extracellular matrix mimics for 3D cell culture”. Biotechnology and Bioengineering 4 (2009): 655-663.
12. Karami P., et al. “A family of intrinsically adhesive injectable and photocurable hydrogels with functional physicochemical performance for regenerative medicine”. Macromolecular Rapid Communications10 (2021): 2000660.