title: Biomineralized composite substrates increase gene expression with nonviral delivery.
abstract: Current strategies to enhance gene transfer have focused on the development of vectors to increase the efficiency of DNA delivery. However, the extracellular matrix and microenvironment have a profound impact on numerous cellular activities including spreading and proliferation; two processes that have been associated with gene transfer efficiency. This study was designed to test the hypothesis that the presence of a biomineralized coating on biodegradable substrates would affect transgene expression following nonviral gene delivery. Thin films were prepared from polymeric microspheres, while biomineralized films were fabricated from microspheres previously soaked in modified simulated body fluid. Mineralized films were significantly more rigid and had widespread mineral coverage compared with nonmineralized substrates. Human mesenchymal stem cells (MSCs) were cultured on biomineralized or nonmineralized films and transfected with plasmid DNA condensed with linear polyethyleneimine (PEI). Compared with cells transfected on nonmineralized films, increases in gene expression were detected in the presence of biomineral at all charge ratios examined. We observed increased uptake of both PEI and DNA by cells on mineralized films. The results of these studies offer an approach to modulate gene delivery and improve the potential benefit of nonviral gene delivery approaches.
authors.affiliation: Department of Biomedical Engineering, University of California, Davis, California 95616, USA.
authors.forename: Rameshwar R
authors.initials: RR
authors.lastname: Rao
authors.forename: Jiawei
authors.initials: J
authors.lastname: He
authors.forename: J Kent
authors.initials: JK
authors.lastname: Leach
mesh_terms: D000818:Animals; D001031:Apatites / Q000737:chemistry; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004548:Elasticity; D005109:Extracellular Matrix / Q000737:chemistry; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology; D011094:Polyethyleneimine / Q000737:chemistry / Q000378:metabolism; D011100:Polyglycolic Acid / Q000737:chemistry / Q000378:metabolism; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D013499:Surface Properties; D019076:Transgenes
chemical_list: D001031:Apatites; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011094:Polyethyleneimine; D004247:DNA