Visible light-curable water-soluble chitosan derivative, chitosan hydrogel, and preparation method: a patent evaluation of US2019202998A1

ABSTRACT

Introduction: Water soluble polysaccharides are versatile structural materials that can be used for the design of biocompatible hydrogels and wet dressings in wound healing applications. Glycol chitosan (GC) is an example of a multifunctional water-soluble chitosan derivative that has inherent wound healing properties and reactive sites for chemical modification.

Areas covered: United States (US) patent US2019202998A1 describes the preparation of a novel wound healing technology based on a three-dimensional (3D) crosslinked GC hydrogel (GCH) wet dressing, prepared via the synthesis of PEG1K-biscarboxylic acid-g-Glycol Chitosan-g-methacrylate using visible light induced photocrosslinking. The selected polymeric network enables the encapsulation of additional growth factors or bioactives on reactive sites. Wet dressings in US2019202998A1 were evaluated against a commercially available control for in vitro release, cytotoxicity, and in vivo wound healing ability in a preliminary mouse model, with the overall wound healing performance consistent with related GC-based hydrogels.

Expert opinion: Comprehensive biocompatibility and antimicrobial testing of the hydrogel is not reported in US2019202998A1, and is recommended as further work to enable clinical applicability. The invention disclosed in US2019202998A1 can potentially be integrated with 3D bioprinting and sensor technology for the preparation of ‘smart’ hydrogel wound dressings, and is a potential area for future research.

KEYWORDS:

• Glycol chitosan hydrogel
• water soluble chitosan derivative
• visible light cured hydrogel
• growth factors
• denaturation
• wet dressing
• wound healing

Article highlights

• Visible light curing of water-soluble glycol chitosan derivatives in the presence of riboflavin for the preparation of hydrogels for wet dressings

• Encapsulation of one or more growth factors enabled by crosslinked networks in hydrogels

• Encapsulation of water-soluble curcumin cyclodextrin inclusion complex

• Performance of wet dressings assessed in a preliminary in vivo mouse excisional wound model

• Glycol Chitosan hydrogel facilitates accelerated wound healing alone, with one or more growth factors, or with a curcumin inclusion complex

List of Abbreviations:

bFGF: Basic Fibroblast Growth Factor; β-CD: β-cyclodextrin; BMP-2: Bone Morphogenetic Protein 2; CUR: Curcumin; DOX HCl: Doxorubicin hydrochloride; EGF: Epidermal Growth Factor; GC: Glycol Chitosan; GC-Hydrogel: Glycol Chitosan Hydrogel; GCH: Glycol Chitosan Hydrogel; GelMA: Gelatin methacryloyl; GM: Glycidyl methacrylate; ic: inclusion complex; MeHA: Methacrylated hyaluronic acid; MT: Masson’s Trichrome; PDGF-BB: Platelet-Derived Growth Factor-BB; PEGDA: Poly(ethylene glycol) diacrylate; PEG: Polyethylene glycol; PTX: Paclitaxel; RF: Riboflavin; TGF-β1: Transforming Growth Factor-β1; 3D: Three-dimensional; UV: Ultraviolet; VEGF: Vascular Endothelial Growth Factor; VLC: Visible light curing

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was funded by the National Research Foundation (NRF) of South Africa.