• 폴리머
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• 제39권1호
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• pp.40-45
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• 2015

혈항혈전성 표면의 제조를 위해 간단한 비용매 휘발 방법을 통하여 고탄성체이면서 생분해성 폴리 락티드-카프로락톤 공중합체 필름의 표면상에 연잎 구조물과 유사한 마이크로 돌기를 만들어 주었다. 표면 구조와 소수성도, 항혈전 효과 등을 시험했으며, 결정화도와 탄성회복률 등의 물리적 특성도 분석하였다. 그 결과 비용매와 메틸렌클로라이드의 혼합 부피비 1:2에서 연잎표면과 유사한 최적의 효과를 얻었으며, 이때 수접촉각은 $124^{\circ}$였다. 혈소판 부착시험에서는 처리하지 않는 군에 비해 약 10%만 부착되는 효과를 확인할 수 있었다.

• Macromolecular Research
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• 제11권4호
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• pp.207-223
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• 2003

For last five years, we are developing the novel local drug delivery devices using biodegradable polymers, especially polylactide (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) due to its relatively good biocompatibility, easily controlled biodegradability, good processability and only FDA approved synthetic degradable polymers. The relationship between various kinds of drug [water soluble small molecule drugs: gentamicin sulfate (GS), fentanyl citrate (FC), BCNU, azidothymidine (AZT), pamidronate (ADP), $1,25(OH)_2$ vitamin $D_3$, water insoluble small molecule drugs: fentanyl, ipriflavone (IP) and nifedipine, and water soluble large peptide molecule drug: nerve growth factor (NGF), and Japanese encephalitis virus (JEV)], different types of geometrical devices [microspheres (MSs), microcapsule, nanoparticle, wafers, pellet, beads, multiple-layered beads, implants, fiber, scaffolds, and films], and pharmacological activity are proposed and discussed for the application of pharmaceutics and tissue engineering. Also, local drug delivery devices proposed in this work are introduced in view of preparation method, drug release behavior, biocompatibility, pharmacological effect, and animal studies. In conclusion, we can control the drug release profiles varying with the preparation, formulation and geometrical parameters. Moreover, any types of drug were successfully applicable to achieve linear sustained release from short period ($1{\sim}3$ days) to long period (over 2 months). It is very important to design a suitable formulation for the wanting period of bioactive molecules loaded in biodegradable polymers for the local delivery of drug. The drug release is affected by many factors such as hydrophilicity of drug, electric charge of drug, drug loading amount, polymer molecular weight, the monomer composition, the size of implants, the applied fabrication techniques, and so on. It is well known that the commercialization of new drug needs a lot of cost of money (average: over 10 million US dollar per one drug) and time (average: above 9 years) whereas the development of DDS and high effective generic drug might be need relatively low investment with a short time period. Also, one core technology of DDS can be applicable to many drugs for the market needs. From these reasons, the DDS research on potent generic drugs might be suitable for less risk and high return.

• 폴리머
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• 제30권2호
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• pp.168-174
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• 2006

기존의 고분자 지지체의 소수성 및 세포친화성을 향상시켜 조직공학용 고기능성 지지체로 사용하기 위해서 여러 가지 플라스마 처리와 카복실기를 함유한 아크릴산(AA)을 직접 chamber내에서 in situ 그래프트 결합을 행하여 최적의 친수성을 갖는 생분해성 poly(L-lactic acid) (PLLA) 필름 및 이중기공 지지체를 제조하였다. 표면분석 결과, 표면개질된 비다공성 PLLA 필름 및 이중기공 지지체 표면은 미처리 PLLA control에 비해서 접촉각의 감소와 카복실기 함량의 증가로 친수성이 크게 증가하였다. 특히 여러 가지 표면개질 방법 중 Ar(아르곤)/AA 시료나 Ar+TP(열중합) 시료보다는 Ar 플라스마와 AA를 차례로 처리한 Ar+AA+AA 시료가 다른 시료들보다 접촉각이 낮고 카복실기가 많아서 최적의 표면 친수화 처리조건임을 알 수 있었으며, 표면개질된 PLLA 필름 및 이중기공 지지체의 경우 친수성이 증가함에 따라서 연골세포의 점착과 증식도 크게 향상되었다.

• 한국환경보건학회지
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• 제25권3호
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• pp.58-63
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• 1999

Biodegradable films were prepared by solution blend method in the weight ratio of chitosan for the purpose of useful biomaterials. The possibility of biomaterials prepared from natural polymer as a skin substitute was evaluated by measuring biocompatibility. These films were inserts in the back of rat and their biodegradability was investigated by the film weight and hematology as a function of time for the biotransformation. The result of rat test showed that medium, high viscosity chitosan induced some suspects of inbiocompatibility in the tissue by goreign body reaction 48 and 72 hours after implantation. Also, we prepared the official burn ointment which is made by low viscosity chitosan. This burn ointment was covered on the skin wound of artificial burn and their effect of healing was investigated by the evaluation of the naked eye and hematological change as a function of time. The result of rats test showed that burn ointments made from chitosan was effective reductio of inflammation than negative group.

• 한국기계가공학회지
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• 제20권11호
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• pp.1-8
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• 2021

In this study, the water resistance and mechanical properties of heat-treated polyvinyl alcohol (PVA)/cellulose nanocrystal (CNC) films were investigated. PVA is the most commonly used synthetic biodegradable polymers owing to its excellent properties. However, the water/moisture sensitivity and relatively poor mechanical properties of PVA limits its applications. Although heat treatment is a conventionally used method to improve the mechanical strength and water resistance of PVA, the effectiveness of this method is insufficient. Therefore, CNC was used to further improve the mechanical properties and water resistance of the heat-treated PVA film. PVA/CNC nanocomposites containing CNC contents of 0, 1, 3, 5, and 10 wt% were fabricated using solvent casting and subsequent heat treatment. The mechanical properties and water resistance of PVA/CNC films were significantly improved. The tensile strength and wet strength of the PVA/CNC film with a CNC content of 5 wt% (PVA/CNC 5%) were 184.5% and 136.0% higher than those of the untreated PVA, respectively. In addition, the water absorption and solubility of PVA/CNC 5% were 56.6% and 68.2% lower than those of the untreated PVA.

• 한국포장학회지
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• 제29권2호
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• pp.103-110
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• 2023

The study aimed to enhance the properties of polylactic acid (PLA), a biodegradable and biocompatible substitute for fossil-based plastics. Since the applicability of PLA has been limited because of its toughness and brittleness, microfibrillated cellulose (MFC) and propolis were introduced into PLA. As a result, the PLA film with MFC/propolis showed significant improvements in mechanical strength, elongation, and storage modulus, while also experiencing a decrease in the glass transition temperature. Additionally, the presence of polyphenols in propolis led to a reduction in light transmittance in the UV wavelength range. These enhancements are attributed to MFC tightly bonding with PLA polymers, and propolis acting as a plasticizer and mediator between MFC and PLA, preventing agglomeration. These reinforced PLA films have the potential to be used in flexible packaging for light-sensitive products.

• 한국포장학회지
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• 제12권2호
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• pp.117-123
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• 2006

유용한 생분해성 필름의 대량생산 시스템에 관한 기초 연구로 키토산과 젤라틴을 이용하여 solution casting 방법으로 비율에 따라 혼합레진을 제조한 후 이를 열 압축기(heat press)로 혼합필름을 제조하였다. 또한, 키토산/젤라틴 혼합필름의 인장강도, 신장률, 색도, 수분 및 산소투과도와 같은 물리적인 특성에 있어 혼합비율이 미치는 효과에 대하여 조사하였다. 혼합비율로 제조된 키토산/젤라틴 혼합필름의 인장강도는 43.43 MPa에서 38.30 MPa로 점차적으로 감소하는 경향을 나타내었고, 신장률은 9.02%에서 15.09%로 인장강도 결과와는 다르게 증가되는 경향을 보였다. 필름의 외관을 결정하는 중요한 특성인 색도측정 결과, L값의 경우 키토산 함량이 증가할수록 혼합필름의 L값은 감소되었고, b값은 L값에 반비례로 증가되었다. 또한, 키토산의 함량이 증가함에 따라 제조된 혼합필름의 ${\Delta}E$ 및 YI 값들은 키토산 함량 15%를 제외하고는 보다 높은 값들로 측정되었다. 수분투과도는 $0.9673mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$에서 $0.8420mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$로 측정되었고, 산소투과도는 혼합비율에 따라 $1.5472{\times}10^{-7}mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$에서 $1.5424{\times}10^{-7}mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$로 측정되었다. Duncan의 다중비교 분석결과로 키토산의 농도가 증가함에 따라 혼합필름의 수분 및 산소투과도는 유의적인(P < 0.05) 차이를 나타내지 않았다.

• 한국환경과학회지
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• 제13권9호
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• pp.827-833
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• 2004

The biodegradability of vinyl acetate acrylate resin and com starch blend was studied by determination of the reduced sugars produced after enzymatic hydrolysis. The starch hydrolysis reaction by $\alpha-amylase$ was achieved within 5 minutes. Optimal ranges of temperature and pH for the starch hydrolysis by $\alpha-amylase$ were around $80^{\circ}C$ and 6.5-7.2, respectively. The biodegradability of the starch-filled acrylate films increased as the content of starch increased. The biodegradation of starch in the starch-filled acrylate film by $\alpha-amylase$ was about 48.6% of that of pure starch. This value of biodegradable starch-filled acrylate film gave a good result with enzymatic shortcut test. The surface morphologies of the starch-filled acrylate film after enzymatic hydrolysis were investigated by scanning electron microscopy (SEM).

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.183-184
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• 2003

Poly(lactic acid) (PLA) is a highly versatile, biodegradable, aliphatic polyester derived from 100% renewable resources, such as corn and sugar beets. Because of the degradation mechanism, PLA is ideally suited for many applications in the environment where recovery of the product is not practical, such as agricultural mulch films and bags. Composting of post consumer PLA items is also a viable solution for many PLA products. (omitted)

• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.680-685
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• 1998

Two kinds of new aliphatic diols were synthesized by the ring-opening reaction of lactide and glycolide with 1,4-butanediol, a difunctional initiator, in the presence of stannous octoate. The resulting aliphatic diols were melt-polymerized with D-tartaric acid at 150 ℃ to produce new crosslinkable polyesters. They were reacted with hexamethylene diisocyanate in THF at 65 ℃ in a teflon mold for 24 h to prepare sequentially ordered crosslinked polyesters (BD/LT/GL/D-tartarate). Degradation of the prepared yellow crosslinked films was carried out in a buffer solution in order to examine the effect of time, pH, temperature and crosslinking degree on their degradation rate and mechanism. The rate of degradation increased with an increase in pH and temperature, but it decreased with increasing degree of crosslinkage incorporated into the crosslinked polyesters. We also found that the crosslinked polymers were converted into the acidic compounds such as lactic, glycolic, and D-tartaric acids during the degradation.