Production and application of biopolymers in drug release Maria Filomena de Andrade Rodrigues (filomena@ipt.br) Laboratory of Industrial Biotechnology Center for Technology of Processes and Products
Biodegradable polymers for drug delivery systems Variety of available degradable polymers - Biocompatibility - free from degradation related toxic products (e.g. monomers, stabilizers, polymerization initiators, emulsifiers) Few approved by FDA 2
Biodegradable polymers for drug delivery systems Polylactic acid (PLA) Polyglycolic acid (PGA) Poly(lactic-co-glycolic acid) (PLGA) Polycaprolactone (PCL) PHA (polyhydroxyalkanoate), specially PHB (polyhydroxybutyrate),
PHA in IPT Development of technology for production of P(3HB) and P(3HB-co-3HV) from sugar cane. Instituto de Pesquisa Tecnológicas do Estado de São Paulo (IPT); Universidade de São Paulo (USP); Copersucar (private company); FINEP Transference to the company PHBISA. Other developments Application of raw materials studied for PHA production (Xylose+glucose from lignocellulose materials, Glycerol/fat acids, vegetable oils and agroindustrial wastes) Development of processes for PHA application for medical application (encapsulation of drugs).
Polyhydroxybutyrate (PHB) and copolymers Polyesters synthesized and used by microorganisms for intracellular energy storage Produced from renewable materials Biodegradable Rate of degradation controlled by varying copolymer composition in vivo PHB degrades to hydroxybutyric acid which is a normal constituent of human blood biocompatible
Polyhydroxyalkanoate chemical structure n = 1 R = -CH 3 R = -CH 2 -CH 3 R = -CH 2 =CH 2 R -CH 2 -CH 2 -CH3 poly(3-hydroxybutyrate) poly(3-hydroxyvalerate) poly(3-hydroxypentenoate) medium-chain-pha Different monomeric compositions
Biodiversity for PHA production Alcaligenes sp. Cupriavidus sp. Burkholderia sp. Pseudomonas sp. Streptomyces sp. Genetic Modified Organism
Metabolic routes for PHA biosynthesis
PHA - Strategies for new developments Objective Reduction of Costs Strategy Isolation and screening Genetic studies Low cost substrates High cell density cultivation Control of molecular weight Substrate flux Mutants deficient in depolymarase Downstream process New polyesters Use of enzymes New susbtrates Isolation of new bacteria Genetic modifications Chemical modifications
PHA production in Brazil Integrated PHB, Sugar and Ethanol Mill Solar Energy CO 2 Sugar Cane Fields Cane Compost Sugar Factory Bagasse Steam Electricity Power Plant Compost Vinasse Molasses Steam Electricity Steam Electricity Sugar Ethanol Yeast Ethanol Distillery Solvents PHB Factory PHB Copersucar Technology Center
PHA applications Thermoplastic properties Packaging industry Medicine - Functionalised nanoparticles Pharmacy - Drug delivery Agriculture Food industry Raw material for enantiomerically pure chemicals Commodities PHA granules in bacteria Microcapsules for controlled drug release Different biopolymers (PHB, PHB/HV, PHPE, PHA MCL ) and applications Scaffolds for tissue engineering
Degradation of PHA Biodegradação (%CO2 total) 100 80 60 40 20 0 0 5 10 15 20 25 30 Tempo (dias) PHB Glicose Padrão (Glicose) Amostra A Inibição
Degradation of PHA Polymer t 10 (days) Vicryl Vabsorbable suture (PLLA 8%-co- 18,8 PGA 92%) Dexon suture (PGA) 22,9 Suture PDS (poly(p-dioxanona) 50,0 PHBV (20% HV) Mw 300.000 Da 229,1 PHBV (12% HV) Mw 350.000 Da 229,1 PHB (0% HV) Mw 800.000 Da 104,2 Reduction of 10% in weight under phisiologic condictions (37 o C, ph 7,4) (HOLLAND, 1986; AMASS et al., 1998).
PHA for drug delivery systems
Technology Spray drying Coacervation Emulsion/solvent extraction PHA for drug delivery systems Micro nanoencapsulation at IPT Gelification Büchi-B190 spray dryer Polymerisation Electrospinning Microfluidics
Burkholderia cepacia Soil bacteria Accumulate a blend of two polyesters P(3H4PE) is produced from sucrose P(3HB) P(3H4PE)
Production of PHA 20 0,7 X, PHA e PHB (g/l) 18 16 14 12 10 8 6 4 2 0 0 10 20 30 40 50 Time (h) 0,6 0,5 0,4 0,3 0,2 0,1 0,0 NH4 e PHPE (g/l) PHB PHA X NH4 PHPE Growth and polymer accumulation by B. cepacia IPT 64 at ph 7.0 and 30 o C.
Purification of PHA by enzymatic lysis of cells
Micro e nanoparticles with biodegradable biopolymers for drug delivery from Burkholderia cepacia as effective biodegradable matrices for drug carriers Burkholderia IPT 64 Fermentation Enzymatic lysis Spray drier Production of cells with 50-60% of PHB-HPE PHB- HPE PHBHPE granules after cell extraction and purification steps - Granules 0.3-1.0 microns, M w -860 kda, Ip - 10 PHBHPE PHBHPE microspheres after spray drying already loaded with the drug NzPC
p Burkholderia cepacia as effective biodegradable matrices for drug carriers Spectroscopic measurements Biodegradation 35x10 6 30 Fluorecence,cps 25 20 15 10 5 700 O.D. Normalized 1.0 0.8 0.6 0.4 0.2 0.0 600 650 700 750 Wavelength,nm 720 740 760 Wavelength, nm 800 780 800 O.D. 5 4,5 4 3,5 3 2,5 2 1,5 1 0,5 0 0 2 6 10 12 24 36 Time (h) Fluorescence emission of NzPC/ PHBPHPE 0.84mM in PBS+10%BSA medium at: 2h( ); 6h(- - -); 12h( - ); 24h( --- ); 36h( - ). Insert: Normalized absorption spectra of NzPC/PHBPHPE (0.84mM in PBS). Absorption measurement (680 nm) of NzPC/PHBPHPE in PBS buffer ( ); NzPC/PHBPHPE in PBS buffer+10% BSA)( ). Release from the NzPC-loaded microspheres during the first 2 hours, followed by a continuous and slowly release until 36 hours in both medium.
Process for production of biodegradable microparticles from granules in aqueous medium. Granules of B. cepacia before (a) and after spray drying (b). Granules of B. cepacia before (a) and after spray drying (b). 100 Spray-dried PHA particles loaded with Acetaminophen (drug : polymer of 1:1) Drug released (% w/w) 80 60 40 20 0 0 300 600 900 1200 1500 Dissolution time (min) Acetaminophen release profiles from spray-dried PHA microparticles loaded with mass ratio of drug : polymer of ( ) 1:1 and ( ) 4:1. The dissolution profile of the drug is presented as reference ( ).
Final Remarks PHBHPE aqueous suspensions are suitable to entrap drugs using the spray drying method to produce a biodegradable drug carrier with a relatively small size and a narrow size distribution and with potential use of PHBPHPE microspheres as an efficient drug delivery system. PHBHPE and other PHA represent new biodegradable materials for application in drug release Diversity of blends and monomer combinations open the possibility for new developments in this field New bio-nanotechnology structure at IPT for new developments
Acknowledgments Research Financial Support IPT Fapesp Finep CNPq Workshop organization CTPP Team Laboratory of Industrial Biotechnology (LBI) Laboratory of Chemical Processes and Particle Technology (LBI) USP Ribeirão Preto
Obrigada! Vielen Danke!