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

Ali-Seyed, Mohamed; Vijayaraghavan, Kavitha

doi:10.9734/arrb/2018/39648

Cited by 7 publications

(2 citation statements)

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“…Thus, blending chitosan with PVA solutions has the effect of thickening and increasing viscosity. The amino and hydroxyl groups of chitosan form hydrogen bonds with the PVA groups, leading to the formation of uniform nanofibers even at low PVA concentrations [32].…”

Section: Strategies To Increase Residence Time On the Ocular Surfacementioning

confidence: 99%

Strategies for Improving Ocular Drug Bioavailability and Corneal Wound Healing with Chitosan-Based Delivery Systems

et al. 2018

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The main inconvenience of conventional eye drops is the rapid washout of the drugs due to nasolacrimal drainage or ophthalmic barriers. The ocular drug bioavailability can be improved by either prolonging retention time in the cul-de-sac or by increasing the ocular permeability. The focus of this review is to highlight some chitosan-based drug delivery approaches that proved to have good clinical efficacy and high potential for use in ophthalmology. They are exemplified by recent studies exploring in-depth the techniques and mechanisms in order to improve ocular bioavailability of the active substances. Used alone or in combination with other compounds with synergistic action, chitosan enables ocular retention time and corneal permeability. Associated with other stimuli-responsive polymers, it enhances the mechanical strength of the gels. Chitosan and its derivatives increase drug permeability through the cornea by temporarily opening tight junctions between epithelial cells. Different types of chitosan-based colloidal systems have the potential to overcome the ocular barriers without disturbing the vision process. Chitosan also plays a key role in improving corneal wound healing by stimulating the migration of keratinocytes when it is used alone or in combination with other compounds with synergistic action.

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Section: Strategies To Increase Residence Time On the Ocular Surfacementioning

confidence: 99%

Strategies for Improving Ocular Drug Bioavailability and Corneal Wound Healing with Chitosan-Based Delivery Systems

et al. 2018

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“…The combination of PVA and chitosan was declared to have comparable optical transmittance and swelling ratio to the native cornea and in vitro evaluation showed 90% viability of human corneal epithelial cells. Nevertheless, more in vivo studies are required to investigate the inflammatory immune response of this mixture [206].…”

Section: Hydrogel-based Scaffoldsmentioning

confidence: 99%

Bioengineering Approaches for Corneal Regenerative Medicine

Mahdavi

Abdekhodaie

Mashayekhan

et al. 2020

Tissue Eng Regen Med

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BACKGROUND: Since the cornea is responsible for transmitting and focusing light into the eye, injury or pathology affecting any layer of the cornea can cause a detrimental effect on visual acuity. Aging is also a reason for corneal degeneration. Depending on the level of the injury, conservative therapies and donor tissue transplantation are the most common treatments for corneal diseases. Not only is there a lack of donor tissue and risk of infection/rejection, but the inherent ability of corneal cells and layers to regenerate has led to research in regenerative approaches and treatments. METHODS: In this review, we first discussed the anatomy of the cornea and the required properties for reconstructing layers of the cornea. Regenerative approaches are divided into two main categories; using direct cell/growth factor delivery or using scaffold-based cell delivery. It is expected delivered cells migrate and integrate into the host tissue and restore its structure and function to restore vision. Growth factor delivery also has shown promising results for corneal surface regeneration. Scaffold-based approaches are categorized based on the type of scaffold, since it has a significant impact on the efficiency of regeneration, into the hydrogel and non-hydrogel based scaffolds. Various types of cells, biomaterials, and techniques are well covered. RESULTS: The most important characteristics to be considered for biomaterials in corneal regeneration are suitable mechanical properties, biocompatibility, biodegradability, and transparency. Moreover, a curved shape structure and spatial arrangement of the fibrils have been shown to mimic the corneal extracellular matrix for cells and enhance cell differentiation. CONCLUSION: Tissue engineering and regenerative medicine approaches showed to have promising outcomes for corneal regeneration. However, besides proper mechanical and optical properties, other factors such as appropriate sterilization method, storage, shelf life and etc. should be taken into account in order to develop an engineered cornea for clinical trials.

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