Biodegradable PEG-Based Amphiphilic Block Copolymers for Tissue Engineering Applications

Abstract

Biodegradable tissue engineering scaffolds have great potential for delivering cells/therapeutics and supporting tissue formation. Polyesters, the most extensively investigated biodegradable synthetic polymers, are not ideally suited for diverse tissue engineering applications due to limitations associated with their hydrophobicity. This review discusses the design and applications of amphiphilic block copolymer scaffolds integrating hydrophilic poly(ethylene glycol) (PEG) blocks with hydrophobic polyesters. Specifically, we highlight how the addition of PEG results in striking changes to the physical properties (swelling, degradation, mechanical, handling) and biological performance (protein & cell adhesion) of the degradable synthetic scaffolds in vitro. We then perform a critical review of how these in vitro characteristics translate to the performance of biodegradable amphiphilic block copolymer-based scaffolds in the repair of a variety of tissues in vivo including bone, cartilage, skin, and spinal cord/nerve. We conclude the review with recommendations for future optimizations in amphiphilic block copolymer design and the need for better-controlled in vivo studies to reveal the true benefits of the amphiphilic synthetic tissue scaffolds.

Development of bioactive electrospun scaffolds suitable to support skin fibroblasts and release Lucilia sericata maggot excretion/secretion

“…In this study, no significant differences were found in terms of wettability between both materials (PCL and PCL-b-PEG/PCL scaffolds) however the measurement of wettability may have been affected by the roughness of the electrospun scaffolds. We found that the PCL-b-PEG/PCL significantly improved cellular infiltration and biocompatibility compared with PCL scaffolds which is in line with findings reported by others [29,34]. These scaffolds had the same fibre diameter and therefore we attribute these finding to differences in chemical composition due to the moisture-rich environment that PEG creates around cells adherent to the scaffolds [35].…”

“…Blends of PEG-PCL polymers have been used as a strategy to modify the mechanical properties, wettability, biocompatibility, and solubility of these scaffolds in water and thus accelerate the degradability of the scaffolds [29,30]. The mechanical properties of scaffolds designed for the treatment of skin lesions should match those of the skin itself [31].…”

Sodium cholate-enhanced polymeric micelle system for tumor-targeting delivery of paclitaxel

“…Monomethoxy(polyethylene glycol)-block-poly(d,l-lactide) (mPEG-PDLLA) is one of the most widely used materials to construct micelles, and has been approved by the US Food and Drug Administration as a pharmaceutical excipient. 8 Genexol PM, one type of mPEG-PDLLA-based PTX-loaded polymeric micelles, has been approved for the treatment of various cancers in several countries in Asia. This formulation has shown significantly decreased toxicity when compared to Taxol (a clinically available PTX formulation).…”

Macroscopic and microscopic shape memory effects of block copolymers prepared via ATRP

“…4 The properties of the SME have allowed SMPs to be widely used in several fields, such as biomedicine, textile, and engineering fields. [5][6][7][8] Thereby, there is an increasing demand for the fabrication of various kinds of SMPs to expand their utility in a spectrum of applications. Since it has been demonstrated that the combination of the suitable fixation phase and reversible phase leads to the development of SMPs, the capability of binding together two or more polymer chains, which possess different structures and physical characteristics, is demonstrated within BCPs.…”

“…Therefore, they are considered as potential candidates for preparation of SMPs. 6,[9][10][11][12][13] BCPs have attracted broad attention due to their precisely tunable structure, as well as the ability to prepare BCPs targeting a broad range of potential applications. [14][15][16][17][18] To date, a variety of synthetic strategies have been developed for synthesis of BCPs.…”