• 제목/요약/키워드: lactide

검색결과 277건 처리시간 0.023초

Medial Wall Orbital Reconstruction using Unsintered Hydroxyapatite Particles/Poly L-Lactide Composite Implants

  • Park, Hojin;Kim, Hyon-Surk;Lee, Byung-Il
    • 대한두개안면성형외과학회지
    • /
    • 제16권3호
    • /
    • pp.125-130
    • /
    • 2015
  • Background: Poly-L-lactide materials combined with hydroxyapatite (u-HA /PLLA) have been developed to overcome the drawbacks of absorbable materials, such as radiolucency and comparably less implant strength. This study was designed to evaluate the usefulness of u-HA/PLLA material in the repair of orbital medial wall defects. Methods: This study included 10 patients with pure medial wall blow-out fractures. The plain radiographs were taken preoperatively, immediately after, and 2 months after surgery. The computed tomography scans were performed preoperatively and 2 months after surgery. Patients were evaluated for ease of manipulation, implant immobility, rigidity and complications with radiologic studies. Results: None of the patients had postoperative complications, such as infection or enophthalmos. The u-HA/PLLA implants had adequate rigidity, durability, and stable position on follow-up radiographic studies. On average, implants were thawed 3.4 times and required 14 minutes of handling time. Conclusion: The u-HA/PLLA implants are safe and reliable for reconstruction of orbital medial wall in terms of rigidity, immobility, radiopacity, and cost-effectiveness. These thin yet rigid implants can be useful where wide periosteal dissection is difficult due to defect location or size. Since the u-HA/PLLA material is difficult to manipulate, these implants are not suitable for use in complex 3-dimensional defects.

Simvastatin loaded porous poly(lactide-co-glycolide)(PLGA) microspheres as delivery systems strategies for injuring tissue and invitro study

  • Bao, Trinh-Quang;Kim, Yang-Hee;Lee, Byong-Taek
    • 한국재료학회:학술대회논문집
    • /
    • 한국재료학회 2009년도 추계학술발표대회
    • /
    • pp.38.2-38.2
    • /
    • 2009
  • Regeration of natural tissuesor to create biological substitutes for defective or lost tissues and organs through the use of cells. In addition to cells and their porous, drugs are required to promote tissue regeneration. Therefore, the present studies were prepared using simvastatim loaded porous poly(lactide-co-glycolide) (PLGA) by double emulsion solvent evaporation water-in-oil-in-water technique (W/O/W) as drug delivery system strategies for injuring tissue. The resulting microspheres were evaluated for morphology, particle size, encapsulation efficiency, degradation of PLGA microspheres in vitro drug release and in vitro cell viability. Scanning electronic microscopic (SEM) showed that the porosities of the particles was changed by experimental conditions and cultured cells were attached well on porous microspheres surface. The X-ray diffraction (XRD) and differential scanning calometry (DSC) analysis indicate thatsimvastatim was highly dipersed in the microsphere at amorphousstate.

  • PDF

1,3-Butadiene diepoxide로 가교된 히아루론산 막의 응용 (Application of Hyaluronic Acid Membrane Cross-linked with 1,3-Butadiene Diepoxide)

  • 정성일;한광선;배정은;김인섭
    • 멤브레인
    • /
    • 제18권2호
    • /
    • pp.124-131
    • /
    • 2008
  • 조직공학용 생체 물질로 사용하고자 가교제 1,3-butadiene diepoxide (BD)를 사용하여 락타이드와 가교시킨 히아루론산 막을 제조하였다. 막의 락타이드 및 BD 반응도는 핵자기 공명 분광볍으로 결정하였다. BD 농도가 높을 경우 6%이하의 성장저해 현상이 나타났으나 그 값은 세포 성장에 문제되지 않을 정도로 충분히 낮았다. 가교온도가 낮을수록 탄성 율은 증가하고 팽윤도는 감소하였다. 막의 생분해속도는 가교온도가 낮을수록 감소하였다. 약물방출 실험 결과 가교 온도가 낮을수록 막을 통한 약물 투과는 감소하였다.

Effect of HPLC Analytical Procedure upon Determining Drug Content in PLGA Microspheres

  • Heo, Sun-Ju;Lee, Hong-Hwa;Lee, Min-Jung;Sah, Hong-Kee
    • Journal of Pharmaceutical Investigation
    • /
    • 제40권3호
    • /
    • pp.193-200
    • /
    • 2010
  • The objective of this study was to investigate the effects of sample preparation, HPLC conditions and peak measurement methods upon determining progesterone content of poly-d,l-lactide-co-glycolide microspheres. A series of the microspheres with different formulations was first prepared. To determine their actual drug contents, the microspheres were dissolved in tetrahydrofuran and diluted with various amounts of methanol to precipitate the polymer. After removal of polymeric precipitates, the filtrates were subject to HPLC analysis under versatile experimental conditions. Interestingly, the composition of a sample solution (e.g., the ratio of methanol to tetrahydrofuran) affected the magnitudes of both peak fronting and peak broadening of progesterone. Its peak became broader and more asymmetrical at lower methanol:tetrahydrofuran ratios. Furthermore, its peak height was influenced by the proportion of tetrahydrofuran in a sample solution. Such problems encountered with tetrahydrofuran were exacerbated when a larger volume of the sample solution was injected onto an analytical column. Under our experimental conditions a peak area measurement provided more accurate and reliable determination of progesterone content in various microspheres than a peak height determination. Optimizing the composition of a sample solution, HPLC chromatographic conditions and peak analysis methods was a prerequisite to an accurate determination of progesterone encapsulated within microspheres.

Effect of Peptide Charge on the Formation of Acylated Peptide Impurities in PLGA Formulations

  • Na, Dong-Hee
    • Journal of Pharmaceutical Investigation
    • /
    • 제41권2호
    • /
    • pp.91-94
    • /
    • 2011
  • The purpose of this study was to investigate the effect of peptide charge on the interaction between peptide and poly(D,L-lactide-co-glycolide) (PLGA) for evaluating mechanism of acylated peptide formation in PLGA matrix. As a model peptide, octreotide, a synthetic somatostatin analogue and active ingredient of commercial PLGA product, was used. The disulfide group of octreotide was reduced with dithiothreitol and the sulfhydryl groups were modified with N-${\beta}$-maleimidopropionic acid (BMPA) to neutralize octreotide with positive charge in physiological conditions. The BMPA-conjugated octreotide was identified by measuring the molecular mass with liquid chromatography-mass spectrometry. In the interaction study with PLGA, native octreotide showed initial adsorption to PLGA and substantial production of acylated peptides (56% of overall peptide), whereas BMPA-conjugated octreotide showed minimal adsorption to PLGA and no acylation products for 42 days. Consequently, the neutralization of octreotide completely inhibited the peptide acylation by preventing interaction of peptide with PLGA. In conclusion, this study demonstrates that the initial polymer interaction of peptide is important step for peptide acylation in PLGA matrix and suggests the modulation of peptide charge as strategy for inhibiting the formation of acylated peptide impurities.