Cryopreservation of implantable human skeletal muscle-derived cell-microcarrier combinations for use in clinical regenerative medicine

Regenerative medicine therapies include tissue engineered constructs to restore tissue and organ function. Among the different approaches, implantable polymeric microcarriers have been proposed for delivery of anchorage-dependent cells to target tissue locations. Cell-microcarrier combinations produced as fresh advanced therapy medicinal products (ATMP) face significant challenges in terms of manufacturing and in time distribution. In the current study, we have explored the feasibility cryopreservation for human skeletal muscle-derived cell (SMDC) – implantable microcarrier combinations. Existing and novel cryoprotectant formulations combined with slow cooling were investigated, along with rapid and slow thawing regimens. Under specific conditions following cryopreservation and thawing, most SMDC cells were viable and remained attached to the microcarriers. Furthermore, the capacity of human SMDC to differentiate into myotubes was unaffected. The cryopreservation process did not alter the physico-mechanical properties of the microcarriers enabling them to retain their primary function of an implantable cell substrate. Overall, these findings pave the way to use cold-chain product supply for future clinical studies with the implantable cell-microcarrier technology

Promotion of Proangiogenic Secretome from Mesenchymal Stromal Cells via Hierarchically Structured Biodegradable Microcarriers

Adipose‐derived mesenchymal stromal cells (AdMSC) release numerous soluble factors capable of stimulating angiogenesis. Improved methods for delivering these cells to maximize their potency are now sought that ideally they retain viable cells in the target tissue while promoting the secretion of angiogenic factors. Substrate surface topography is a parameter that can be used to manipulate the behavior of AdMSC but challenges exist with translating this parameter into materials compatible with minimally invasive delivery into tissues for in situ delivery of the angiogenic secretome. The current study investigates three compositions of hierarchically structured, porous biodegradable microcarriers for the culture of AdMSC and the influence of their surface topographies on the angiogenic secretome. All three compositions perform well as cell microcarriers in xeno‐free conditions. The attached AdMSC retain their capacity for subsequent trilineage differentiation. The secretome of AdMSC attached to the microcarriers consists of multiple proangiogenic factors, including significantly elevated levels of vascular endothelial growth factor, which stimulates angiogenesis in vitro. The unique properties of hierarchically structured, porous biodegradable microcarriers investigated in this study offer a radically transformative approach for achieving targeted in vivo delivery of AdMSC and enhancing the potency of their proangiogenic activity to induce neovascularization in ischemic tissue

Cells on hierarchically-structured platforms hosting functionalized nanoparticles

In this work, we report on a novel approach to develop hierarchically-structured cell culture platforms incorporating functionalized gold nanoparticles (AuNPs). In particular, the hierarchical substrates comprise primary pseudo-periodic arrays of silicon microcones combined with a secondary nanoscale pattern of homogenously deposited AuNPs terminated with bio-functional moieties. AuNPs with various functionalities (i.e. oligopeptides, small molecules and oligomers) were successfully attached onto the microstructures. Experiments with PC12 cells on the hierarchical substrates incorporating AuNPs carrying the RGD peptide showed an impressive growth and NGF-induced differentiation of the PC12 cells, compared to that on the NPs-free, bare, micropatterned substrates. The exploitation of the developed methodology for the binding of AuNPs as carriers of specific bio-functional moieties onto micropatterned culture substrates for cell biology studies is envisaged