Readily Adsorbable Thermoresponsive Polymers for the Preparation of Smart Cell-Culturing Surfaces on Site

Abstract

The efficacy of several cell therapy products is directly impacted by trypsinization, which can diminish the engrafting capacity of transplanted cells by cleaving cell surface receptors. Thermoresponsive surfaces can alleviate this drawback, enabling temperature-driven and enzyme-free cell harvesting. However, the production of thermoresponsive surfaces relies on dedicated and complex equipment, often involving protocols dependent on high surface activation energies that prevent the development of scalable and universal platforms. In this work, we developed thermoresponsive copolymers incorporating styrene units that enable the copolymer adsorption on tissue culture polystyrene surfaces from an alcoholic solution in a short time, regardless of the vessel size and geometry, and without any particular equipment. In this way, the procedure can be performed with minimal effort by the end user on any surface. The thermoresponsive copolymers were synthesized via reversible addition–fragmentation chain transfer polymerization, providing high control over the polymer microstructure, a key parameter for tuning its cloud point and architecture. Block copolymers comprising a thermoresponsive segment and a polystyrene block exhibited optimal adhesion on conventional cell culture surfaces and permitted a more efficient temperature-mediated harvesting of adipose-derived stromal cells and Chinese hamster ovary cells compared to their statistical counterparts. To expand the application of this polymer deposition protocol to serum-free cell culture, we also considered the polymer modification with the tripeptide arginine-glycine-aspartic acid, known to promote the cell adhesion to synthetic substrates. The incorporation of this peptide enabled the collection in serum-free conditions of intact cell sheets from surfaces prepared shortly before their usage.

Thermoresponsive Modular Nano-Objects Via RAFT Dispersion Polymerization in a Non-Polar Solvent

“…In this context, the reversible addition–fragmentation chain transfer (RAFT) polymerization offers an important alternative when high control over the polymer composition and microstructure is required. , An important example is represented by the possibility of synthesizing well-defined block copolymers with high blocking efficiency, poor interchain compositional drift, and organized into nano-objects both in organic and aqueous solvents via RAFT polymerization-induced self-assembly (PISA). − The outstanding level of control over the structure of the copolymer offered by this pseudoliving polymerization proved to be decisive in the fine modulation of important properties of the produced nano-objects, including their morphology, average size, and, more recently, their phase separation in response to thermal stimuli. − As a matter of fact, the so-called thermoresponsive polymers are interesting materials able to sharply and often reversibly change their miscibility with a given solvent at a critical temperature, generally called cloud point ( T cp ). , According to how their solubility changes with temperature, these materials can be divided into polymers with a Lower or Upper Critical Solution Temperature (LCST or UCST) if they become more insoluble in the outer phase with increasing or decreasing temperature, respectively. − By starting from this general concept, it was demonstrated that the bulk response of formulations of these smart materials depends upon the polymer microstructure. In particular, block copolymers comprising a solvophilic segment and a thermoresponsive one can undergo a reversible self-assembly into nano-objects, whose morphology is dictated, as for low molecular weight surfactants, by the packing parameter .…”

Thermoresponsive polymers with LCST transition: synthesis, characterization, and their impact on biomedical frontiers

“…With cell sheet engineering, tissue-specific cells can be used for the fabrication of physically connective, functionally synchronous three-dimensional tissues. 64 In the case of cell-based therapies, thermoresponsive polymers serve as a good platform for scaffold-free cell growth as they permit little to no immune rejection, and display greater regenerating properties compared to directly injected suspended cells. This type of biomaterials has found applications in orthopaedic tissue engineering, wound healing, oral disease treatments, and neural and corneal tissue therapy (Fig.…”

“…These polymers have gained significant attention in recent years 41–49 due to their potential applications in several biomedical fields such as bioimaging, 50 drug delivery, 51–56 injectables, 57–63 smart surfaces, 64–75 adhesives, 76 and tissue engineering. 77–80 However, the effects of the structural heterogeneity of polymers on thermal transition and modern characterization techniques have not been systematically discussed before.…”

Polymeric Systems for Cancer Immunotherapy: A Review

“…Notably, utilizing engineered polymers can improve and streamline CAR-T cell manufacturing process. Diverse kinds of polymers have been synthesized and modified to apply in many medical engineering processes including cell culture ( 99 ), tissue engineering ( 100 ), separation ( 101 ), and drug and gene delivery ( 102 ). Similarly, many polymeric systems have been used to optimize streamlined CAR-T cell manufacturing process, mainly focusing on activation and genetic modification of the CAR-T cell.…”