In vitro cell delivery by gelatin microspheres prepared in water-in-oil emulsion

Abstract

The regeneration of injured or damaged tissues by cell delivery approaches require the fabrication of cell carriers (e.g., microspheres, MS) that allow for cell delivery to limit cells spreading from the injection site. Ideal MS for cell delivery should allow for cells adhesion and proliferation on the MS before the injection, while they should allow for viable cells release after the injection to promote the damaged tissue regeneration. We optimized a water-in-oil emulsion method to obtain gelatin MS crosslinked by methylenebisacrylamide (MBA). The method we propose allowed obtaining spherical, chemically crosslinked MS characterized by a percentage crosslinking degree of 74.5 ± 2.1%. The chemically crosslinked gelatin MS are characterized by a diameter of 70.9 ± 17.2 µm in the dry state and, at swelling plateau in culture medium at 37 °C, by a diameter of 169.3 ± 41.3 µm.The MS show dimensional stability up to 28 days, after which they undergo complete degradation.Moreover, during their degradation, MS release gelatin that can improve the engraftment of cells in the injured site. The produced MS did not induce any cytotoxic effect in vitro and they supported viable L929 fibroblasts adhesion and proliferation. The MS released viable cells able to colonize and proliferate on the tissue culture plastic, used as release substrate, potentially proving their ability in supporting a simplified in vitro wound healing process, thus representing an optimal tool for cell delivery applications.

Fabrication of a Vitamin B12-Loaded Carbon Dot/Mixed-Ligand Metal Organic Framework Encapsulated within the Gelatin Microsphere for pH Sensing and In Vitro Wound Healing Assessment

“…Thus, we can conclude that the delivery of vitamin B12 at the injured site may be responsible for the proliferation of resident fibroblast cells and tissue regeneration1. Moreover, the release of gelatin during the MS degradation may compensate for the crisis of collagen, which plays an integral role in wound closure …”

“…Their large surface area allows better cell adhesion to and proliferation in damaged sites. However, an MS made of a synthetic polymer sometimes produces a local inflammatory response during its degradation. , …”

Scaffold-based developmental tissue engineering strategies for ectodermal organ regeneration

“…Naturally derived materials such as collagen [ 109 ] and decellularized tooth bud [ 111 ] were also used for cell-seeded strategies, as alternatives to the described synthetic polymer-based scaffolds. As an advantage, the choice of naturally derived polymers such as collagen, collagen derivatives and decellularized matrix provides an ECM-biomimetic environment [ [123] , [124] , [125] ], thus avoiding the need for coating procedures to promote cell adhesion which is required for synthetic polymer-based scaffolds (e.g. collagen coating) [ 108 , 113 ].…”

Type II Collagen-Conjugated Mesenchymal Stem Cells Micromass for Articular Tissue Targeting

“…Generally, cell therapies for OA are safe, albeit their reported efficacy from several randomized trials is quite controversial [ 10 ]. This is due to the high variability in the cell preparation and lack of rigors in the trials that preceded its clinical shortcoming [ 11 ]. An argument was made, in which the improvements seen among patients in the trials who received MSCs injection were only transient, only to be followed with significant cell apoptosis following injection [ 12 ].…”

“…Microspheres are historically known for their role in drug delivery systems and in vitro cellular expansion [ 11 , 16 ]. Little was known about their role in cell delivery until several reports demonstrated their safety and efficacy in delivering cells for cartilage regeneration in vivo [ 17 , 18 ].…”