title: Improving the stability of chitosan-gelatin-based hydrogels for cell delivery using transglutaminase and controlled release of doxycycline.
abstract: Although local cell delivery is an option to repair tissues, particularly using chitosan-based hydrogels, significant attrition of injected cells prior to engraftment has been a problem. To address this problem, we explored the possibility of stabilizing the chitosan-gelatin (CG) injectable hydrogels using (1) controlled release of doxycycline (DOX) to prevent premature degradation due to increased gelatinase activity (MMP-2 and MMP-9), and (2) transglutaminase (TG) to in situ cross-link gelatin to improve the mechanical stability. We prepared DOX-loaded PLGA nanoparticles, loaded into the CG hydrogels, measured DOX release for 5 days, and modeled using a single-compartmental assumption. Next, we assessed the influence of TG and DOX on hydrogel compression properties by incubating hydrogels for 7 days in PBS. We evaluated the effect of these changes on retention of fibroblasts and alterations in MMP-2/MMP-9 activity by seeding 500,000 fibroblasts for 5 days. These results showed that 90 % of DOX released from cross-linked CG hydrogels after 4 days, unlike CG hydrogels where 90 % of DOX was released within the first day. Addition of TG enhanced the CG hydrogel stability significantly. More than 60 % of seeded fibroblasts were recovered from the CG-TG hydrogels at day 5, unlike 40 % recovered from CG-hydrogels. Inhibition of MMP-2/MMP-9 were observed. In summary, controlled release of DOX from CG hydrogels cross-linked with TG shows a significant potential as a carrier for cell delivery.
authors.affiliation: School of Chemical Engineering, Oklahoma State University, 208 Cordell North, Stillwater, OK, 74078, USA.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Tormos
authors.affiliation: School of Chemical Engineering, Oklahoma State University, 208 Cordell North, Stillwater, OK, 74078, USA.
authors.forename: Carol
authors.initials: C
authors.lastname: Abraham
authors.affiliation: School of Chemical Engineering, Oklahoma State University, 208 Cordell North, Stillwater, OK, 74078, USA. sundar.madihally@okstate.edu.
authors.forename: Sundararajan V
authors.initials: SV
authors.lastname: Madihally
mesh_terms: D048271:Chitosan; D004318:Doxycycline / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology; D052816:Foreskin; D006801:Humans; D020100:Hydrogels; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry; D011503:Transglutaminases / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D020100:Hydrogels; D048271:Chitosan; D011503:Transglutaminases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D004318:Doxycycline
keywords: Cell delivery; Chitosan; Doxycycline; Fibroblasts; Gelatin; Hydrogel; MMP; Stability; Transglutaminase