Influence of matrix and bulk behaviour of an injectable hydrogel on the survival of encapsulated cardiac cells

Abstract

Cytocompatibility, suitable porosity, higher equilibrium water content and tissue like elasticity are the demanding criteria required to design a hydrogel for cell encapsulation and delivery. Here a mechanically stable cell supporting synthetic hydrogel was fabricated from poly(propylene fumarate-coethylene glycol)/PEGDA by redox initiating polymerisation for cell encapsulation. A hydrogel prepared with 93.5% poly(propylene fumarate-co-ethylene glycol) and 6.5% PEGDA acquired matrix and bulk characteristics of equilibrium water content (EWC) 84.45 AE 0.80%, freezable water content 67.93%, Young modulus 212.2 AE 0.02 kPa and pore diameter 88.64 AE 18.96 mm. This hydrogel with higher free water content, favourable pore dimensions and mechanical strength was used to encapsulate cardiomyoblasts. The encapsulated cardiomyoblasts were showing increasing viability from 3-30 days with viable green fluorescence. The matrix and bulk characteristics of the hydrogel are favourable and elicited uniform, green fluorescing, live cardiomyoblasts (H9c2) inside with 150% cell viability (MTT assay) and uniform ECM protein distribution after 30 days. The slow in vitro degradation of the hydrogel in physiological-like conditions is favourable for the delivery and retention of the encapsulated cells at the injection site.

In situcrosslinkable elastomeric hydrogel for long-term cell encapsulation for cardiac applications

“…About 10 μm cryosections of cell encapsulated hydrogels were taken using LEICA CM 3050S microtome on a polylysine coated glass slide at −20°C. The sections were stained with hematoxylin and counterstained with eosin as per the published reports . The sections were mounted with CytoSeal mounting medium.…”

“…The weight after swelling was recorded. The hydrogel swelling ratio and equilibrium water content (EWC) were calculated as per the published reports . Crosslink density and molecular weights between crosslinks of hydrogels were identified using modified Flory–Rehner's equation .…”

Stem cells and injectable hydrogels: Synergistic therapeutics in myocardial repair

“…However, some of the materials used for scaffold formation are difficult to handle and highly vulnerable to proteolysis and premature degradation (Shapira-Schweitzer and Seliktar, 2007). According to the above-mentioned limitations, it is reasonable to have a cell-laden scaffold created from an injectable biomaterial with proper handling features and controllable physicochemical properties that does not impede CMs contractions (Bonaros, Rauf, 2008, Komeri et al , 2015). An injectable biomaterial must undergo in situ liquid-to-solid transition with CMs in suspension without harming the cells or the surrounding host myocardium.…”

Infarct Zone: a Novel Platform for Exosome Trade in Cardiac Tissue Regeneration

“…Among the versatile polymeric biomaterials, hydrogel sub-sets have been widely employed owing to their superior biomimetic characters. The diverse qualities of CTE hydrogels were detailed in our recent publications [127], [135][136][137][138][139],. However, the application of hydrogel-based biomaterials for exosome-mediated CTE and cardiac regeneration remains unexplored and the published literature regarding the same are unavailable.…”