Physicochemical Characterization and Bioactivity of an Improved Chitosan Scaffold Cross-Linked With Polyvinyl Alcohol for Corneal Tissue Engineering Applications

Background: Corneal blindness resulting from various medical condition affects millions worldwide. The rapid developing field of tissue engineering offers the potential to develop a tissue-engineered cornea that adheres very closely to the native cornea for transplantation. The design of a scaffold with mechanical properties and transparency similar to that of natural cornea is vital for the regeneration of corneal tissues. Hence, there is a need to investigate this relatively inexpensive but an improved scaffold to assist in human corneal stem cells delivery.

Aim and Study Design: The present study aimed at to prepare and investigate the properties of poly vinyl alcohol (PVA)/chitosan blended scaffold by further cross-linking with 1-Ethyl-3-(3-dimethyl amino propyl)-carbodiimide (EDC), 2 N-Hydroxysuccinimide (NHS) as potential in vitro carrier for human limbal epithelial cells delivery.

Results: After the viscosity measurement, the PVA/Chitosan scaffold was observed by Fourier transform infrared spectroscopy (FT-IR). The water absorbency of PVA/Chitosan was increased 361% by swelling. Compression testing demonstrated that by increasing the amount of chitosan, the strength of the scaffold could be increased to 16 × 10−1 Mega Pascal Pressure Unit (MPa). Our degradation results revealed by mass loss shows that scaffold degraded gradually implies slow degradation but shown enhanced the biomechanical properties. In vitro 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay showed good cell proliferation and growth in the scaffold. Besides the above, the present study aimed at exploring the effects if any observed with PVA/chitosan and other cross linkers on cell morphology and phenotype using H&E staining. Our MTT assay results and the cells observed on these membranes confirmed that the safer and improved method of preparation of membrane could increase the cells adhesion and growth on the substrata.

Conclusion: Hence, we strongly believe the use of this improved PVA/chitosan polymer scaffold has potential to cut down the disadvantages of human amniotic membrane (HAM) for corneal epithelium in ocular surface surgery in future after successful experimentation with clinical trials.