This is a grant renewal for the continuation of studies on controlled release systems for large molecular weight (MW is greater than 1000) drugs. The studies proposed have relevance for controlled release of small molecules as well. The grant first started in 1979. In the past grant period, we have 1) developed new models and Monte-Carlo techniques for analyzing protein transport and have used these approaches to design systems capable of releasing insulin for over 100 days, as well as release systems for other molecules, 2) developed new synthesis procedures for polyanhydrides that have yielded the first high molecular weight ( greater than 40,000) polyanhydrides; synthesized polymers, which can , by the choice of copolymer, degrade in tome periods ranging from 1 week to 3 years; developed microencapsulation approaches for polyanhydrides; conducted toxicology studies on these polymers; and initiated the development of (and created new techniques to analyze for) several new classes of biopolymers for drug delivery including pseudopolyaminoacids, polyiminocarbonates, and polyphosphazenes, 3) quantitated parameters such as magnetic field strength, magnet orientation, field frequency, and polymer composition which regulated a magnetically controlled release system and tested this system in vivo, initiated the development of ultrasonically controlled polymeric delivery systems and examined the effect of ultrasound on transdermal drug delivery; and developed an intelligent controlled release system using enzymes to regulated protein solubility and release rates. We now propose to conduct research in new areas that have grown out of work supported by this grant; 1) fundamental studies of protein inactivation in polymers under physiological conditions and developing rational strategies for stabilizing proteins inside polymers. This will involve a systematic study examining the effects of wetting, selected additives, and physicochemical characteristics of model proteins. Strategies to be examined for stabilizing proteins will involve additives, polymer microenvironment, chemical modification, and site directed mutagenesis, 2) synthesizing and examining a new class of polymers that we have proposed-pseudopolyaminoacids for biological applications. Model pseudopolyaminoacids, based both on hydroxyproline esters and phenylalanine-glutamine amide anhydrides, will be synthesized and characterized.

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National Institute of General Medical Sciences (NIGMS)
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Surgery and Bioengineering Study Section (SB)
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Massachusetts Institute of Technology
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Schroeder, Avi; Goldberg, Michael S; Kastrup, Christian et al. (2012) Remotely activated protein-producing nanoparticles. Nano Lett 12:2685-9
Devitt, Gerard; Thomas, Mini; Klibanov, Alexander M et al. (2007) Optimized protocol for the large scale production of HIV pseudovirions by transient transfection of HEK293T cells with linear fully deacylated polyethylenimine. J Virol Methods 146:298-304
Thomas, Mini; Lu, James J; Zhang, Chengcheng et al. (2007) Identification of novel superior polycationic vectors for gene delivery by high-throughput synthesis and screening of a combinatorial library. Pharm Res 24:1564-71
Sharma, Vikas K; Klibanov, Alexander M (2007) Moisture-induced aggregation of lyophilized DNA and its prevention. Pharm Res 24:168-75
Berry, David; Lynn, David M; Berry, Eric et al. (2006) Heparin localization and fine structure regulate Burkitt's lymphoma growth. Biochem Biophys Res Commun 348:850-6
Thomas, Mini; Ge, Qing; Lu, James J et al. (2005) Cross-linked small polyethylenimines: while still nontoxic, deliver DNA efficiently to mammalian cells in vitro and in vivo. Pharm Res 22:373-80
Sharma, Vikas K; Thomas, Mini; Klibanov, Alexander M (2005) Mechanistic studies on aggregation of polyethylenimine-DNA complexes and its prevention. Biotechnol Bioeng 90:614-20
Colombo, Gaia; Padera, Robert; Langer, Robert et al. (2005) Prolonged duration local anesthesia with lipid-protein-sugar particles containing bupivacaine and dexamethasone. J Biomed Mater Res A 75:458-64
Jia, Xinqiao; Colombo, Gaia; Padera, Robert et al. (2004) Prolongation of sciatic nerve blockade by in situ cross-linked hyaluronic acid. Biomaterials 25:4797-804
Colombo, Gaia; Langer, Robert; Kohane, Daniel S (2004) Effect of excipient composition on the biocompatibility of bupivacaine-containing microparticles at the sciatic nerve. J Biomed Mater Res A 68:651-9

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