Fabrication of multi-layered biodegradable drug delivery device based on micro-structuring of PLGA polymers.
A programmable and biodegradable drug delivery device is desirable when a drug needs to be administered locally. While most local drug delivery devices made of biodegradable polymers relied on the degradation of the polymers, the degradation-based release control is often limited by the property of the polymers. Thus, we propose micro-geometry as an alternative measure of controlling drug release. The proposed devices consist of three functional layers: diffusion control layer via micro-orifices, diffusion layer, and drug reservoir layers. A micro-fabrication technology was used to shape an array of micro-orifices and micro-cavities in 85/15PLGA layers. A thin layer of fast degrading 50/50PLGA was placed as the diffusion layer between the 85/15PLGA layers to prevent any burst-type release. To modulate the release of the devices, the dimension and location of the micro-orifices were varied and the responding in vitro release response of tetracycline was monitored over 2 weeks. The release response to the different micro-geometry was prominent and further analyzed by FEM simulation. Comparison of the experiments to the simulated results identified that the variation of micro-geometry influenced also the volume-dependent degradation rate and induced the osmotic pressure.
Ryu
Won Hyoung
WH
Rapid Prototyping Laboratory, Mechanical Engineering Department, Stanford University, Rm. 226, Bldg. 530, 440 Escondido Mall, Stanford, CA 94305, USA. whryu@stanford.edu
Vyakarnam
Murty
M
Greco
Ralph S
RS
Prinz
Fritz B
FB
Fasching
Rainer J
RJ
D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D044085:Microfluidics / Q000379:methods*; D008863:Microspheres; D008904:Miniaturization; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D013752:Tetracycline / Q000008:administration & dosage / Q000737:chemistry*
D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D013752:Tetracycline