Examination of In vitro and In vivo biocompatibility of alginate-hyaluronic acid microbeads As a promising method in cell delivery for kidney regeneration

In this study, alginate (ALG) and alginate-hyaluronic acid (ALG-HA) injectable microbeads, with the purpose of delivering stem cells for tissue engineering, were prepared by a spraying method into a CaCl2 solution that shows high porosity for the exchange of nutrition and waste. In addition, the size distribution and surface morphology was investigated using optical and scanning electron microscopy, respectively. The chemical structural properties of the ALG-HA microbeads were examined by Fourier transform infrared spectroscopy. The biocompatibility of ALG and ALG-HA microbeads was examined in vitro. Rat bone marrow stem cells were encapsulated in microbeads to investigate cell release, cell viability, proliferation, and secretion of growth factors such as VEGF and PDGF. Growth factors were released for the 21 day experimental period. Cells were found to be released from the microbeads after 7 days. Furthermore, the in vivo biocompatibility of ALG-HA microbeads was examined using microbeads without cell encapsulation in the kidney capsule, in order to assess the foreign body reaction and inflammatory response, for 14 days. The desired in vivo response to ALG-HA microbeads hydrogel makes it an exquisite candidate for subcapsular cell and drug delivery to kidney tissue.