PMID- 10737887
OWN - NLM
STAT- MEDLINE
DCOM- 20000523
LR  - 20190910
IS  - 0021-9304 (Print)
IS  - 0021-9304 (Linking)
VI  - 50
IP  - 3
DP  - 2000 Jun 5
TI  - Controlled release of transforming growth factor beta1 from biodegradable polymer 
      microparticles.
PG  - 440-51
AB  - Recombinant human transforming growth factor beta1 (TGF-beta1) was incorporated 
      into biodegradable microparticles of blends of poly(DL-lactic-co-glycolic acid) 
      (PLGA) and poly(ethylene glycol) (PEG) at 6 ng/1 mg microparticles. Fluorescein 
      isothiocynate labeled bovine serum albumin (FITC-BSA) was coencapsulated as a 
      porogen at 4 microg/1 mg of microparticles. The effects of PEG content (0, 1, or 
      5 wt %) and buffer pH (3, 5, or 7.4) on the protein release kinetics and the 
      degradation of PLGA were determined in vitro for up to 28 days. The entrapment 
      yield of TGF-beta1 was 83.4 +/- 13.1 and 54.2 +/- 12.1% for PEG contents of 0 and 
      5%, respectively. The FITC-BSA and TGF-beta1 were both released in a multiphasic 
      fashion including an initial burst effect. Increasing the PEG content resulted in 
      the decreased cumulative mass of released proteins. By day 28, 3.8 +/- 0. 1 and 
      2.8 +/- 0.3 microg (based on 1 mg microparticles) of loaded FITC-BSA and 3.4 +/- 
      0.2 and 2.2 +/- 0.3 ng of loaded TGF-beta1 were released into pH 7.4 phosphate 
      buffered saline (PBS) from microparticles with 0 and 5% PEG, respectively. 
      Aggregation of FITC-BSA occurred at lower buffer pH, which led to decreased 
      release rates of both proteins. For microparticles with 5% PEG, 2.3 +/- 0.1 
      microg of FITC-BSA and 2.0 +/- 0.2 ng of TGF-beta1 were released in pH 7.4 buffer 
      after 28 days, while only 1.7 +/- 0.3 microg and 1.3 +/- 0.4 ng of the 
      corresponding proteins were released in pH 3 buffer. The degradation of PLGA was 
      also enhanced at 5% PEG content, which was significantly accelerated at acidic pH 
      conditions. The calculated half-lives of PLGA were 20.3 +/- 0.9 and 15.9 +/- 1.2 
      days for PEG contents of 0 and 5%, respectively, in pH 7.4 PBS and 14.8 +/- 0.4 
      and 5.5 +/- 0.1 days for 5% PEG in pH 7.4 and 3 buffers, respectively. These 
      results suggest that PLGA/PEG blend microparticles are useful as delivery 
      vehicles for controlled release of growth factors.
CI  - Copyright 2000 John Wiley & Sons, Inc.
FAU - Lu, L
AU  - Lu L
AD  - Departments of Bioengineering and Chemical Engineering, Rice University, Houston, 
      Texas 77005-1892, USA.
FAU - Stamatas, G N
AU  - Stamatas GN
FAU - Mikos, A G
AU  - Mikos AG
LA  - eng
GR  - R01-AR44381/AR/NIAMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biomed Mater Res
JT  - Journal of biomedical materials research
JID - 0112726
RN  - 0 (Capsules)
RN  - 0 (Drug Implants)
RN  - 0 (Polymers)
RN  - 0 (Transforming Growth Factor beta)
RN  - 1SIA8062RS (Polylactic Acid-Polyglycolic Acid Copolymer)
RN  - 26009-03-0 (Polyglycolic Acid)
RN  - 33X04XA5AT (Lactic Acid)
RN  - 3WJQ0SDW1A (Polyethylene Glycols)
SB  - IM
MH  - Animals
MH  - *Capsules
MH  - Cattle
MH  - *Drug Delivery Systems
MH  - *Drug Implants
MH  - Humans
MH  - *Lactic Acid
MH  - Microscopy, Electron, Scanning
MH  - *Polyethylene Glycols
MH  - *Polyglycolic Acid
MH  - Polylactic Acid-Polyglycolic Acid Copolymer
MH  - *Polymers
MH  - Transforming Growth Factor beta/administration & dosage
OTO - NASA
OT  - Non-programmatic
EDAT- 2000/03/29 09:00
MHDA- 2000/06/08 09:00
CRDT- 2000/03/29 09:00
PHST- 2000/03/29 09:00 [pubmed]
PHST- 2000/06/08 09:00 [medline]
PHST- 2000/03/29 09:00 [entrez]
AID - 10.1002/(SICI)1097-4636(20000605)50:3<440::AID-JBM19>3.0.CO;2-G [pii]
AID - 10.1002/(sici)1097-4636(20000605)50:3<440::aid-jbm19>3.0.co;2-g [doi]
PST - ppublish
SO  - J Biomed Mater Res. 2000 Jun 5;50(3):440-51. doi: 
      10.1002/(sici)1097-4636(20000605)50:3<440::aid-jbm19>3.0.co;2-g.