• 대한의용생체공학회:의공학회지
• /
• 제18권2호
• /
• pp.167-172
• /
• 1997

Novel measurement method has been performed for the noninvasive study of the swelling effect detected in hydrophilic polymers using Magnetic Resonance Microscopy. iN NMR images were acquired to measure geometric changes due to the swelling effect occurred in the polymer specimens. In addition to the geometric changes, the water ingress process was visualized noninvgsively. The measurement method performed .in the present study utilized some of NMR's valuable properties, both noninvasiveness and parameter selectivity. It is believed that the method used in the present study may be applicable to the study of biopolymers in which noninvasiveness is particularly important.

• BMB Reports
• /
• 제49권1호
• /
• pp.26-36
• /
• 2016

Emerging trends for cardiac tissue engineering are focused on increasing the biocompatibility and tissue regeneration ability of artificial heart tissue by incorporating various cell sources and bioactive molecules. Although primary cardiomyocytes can be successfully implanted, clinical applications are restricted due to their low survival rates and poor proliferation. To develop successful cardiovascular tissue regeneration systems, new technologies must be introduced to improve myocardial regeneration. Electrospinning is a simple, versatile technique for fabricating nanofibers. Here, we discuss various biodegradable polymers (natural, synthetic, and combinatorial polymers) that can be used for fiber fabrication. We also describe a series of fiber modification methods that can increase cell survival, proliferation, and migration and provide supporting mechanical properties by mimicking micro-environment structures, such as the extracellular matrix (ECM). In addition, the applications and types of nanofiber-based scaffolds for myocardial regeneration are described. Finally, fusion research methods combined with stem cells and scaffolds to improve biocompatibility are discussed. [BMB Reports 2016; 49(1): 26-36]

• Fibers and Polymers
• /
• 제4권2호
• /
• pp.54-58
• /
• 2003

Previous research on healthcare workers’ protection has concentrated on liquid barrier protection by providing impermeable personal articles such as latex gloves. This property is of high importance but since most blood-borne pathogen transmissions in the healthcare industry are caused by needle-stick injuries, protection from sharp invasive instruments should also be of high concern. And since latex and alike provide no protection against needle-stick injuries, new protective systems need to be developed and evaluated. This part of the study provides a review regarding the current practice of protection and the serious problems that arise from needle-flick injuries. Additionally, the development of new protective system is described. In part II of the study, evaluation of the new system will be provided.

• 대한수의학회지
• /
• 제57권4호
• /
• pp.215-222
• /
• 2017

Temporal and subcellular distributions of hyaluronic acid (HA) as a degradable nanoparticle (NP) in animals were investigated to determine if HA-NP could be utilized as an appropriate drug delivery system. After mice were intravenously injected with 5 mg/kg of Cy5.5-labeled HA-NP sized 350-400 nm or larger HA-polymers, the fluorescence intensity was measured in all homogenized organs from 0.5 h to 28 days. HA-NP was greatly detected in spleen, liver and kidney until day 28, while it was maintained at low levels in other organs. HA-polymer was observed at low levels in all organs. HA-NP quantities in spleen and liver were reduced until day 3, but increased sharply between days 3 and 7, then decreased again, while their HA-polymers were maintained at low levels until day 28. In kidneys, both HA-NP and HA-polymer showed high levels after 0.5 h of administration, but steadily decreased until day 28. According to ultrastructural analyses, HA-NP was engulfed in Kupffer cells of liver and macrophages of spleen and kidney at day 1 and was accumulated in the cytoplasm of kidney tubular cells at day 7. Overall, these findings suggest that HA-NP could be considered a desirable drug carrier in the liver, kidney, or spleen.

• Bulletin of the Korean Chemical Society
• /
• 제33권12호
• /
• pp.3957-3962
• /
• 2012

Iron-oxide nanoparticles (IONs) with biocompatible coatings are the only nanostructural materials which have been approved by the FDA for clinical use. Common biocompatible coatings such as hydrocarbons, polymers, and silica have profound influences on critical characteristics of IONs. Recently, amino acids were introduced as a novel biocompatible coating. In the present study, the effects of amino acids on IONs synthesis and characteristics have been evaluated. Magnetite nanoparticles with L-arginine and L-lysine coatings were synthesised by a coprecipitation reaction in aqueous solvent and their characteristics were compared with naked magnetite nanoparticles. The results showed that amino acids can be a perfect coating for IONs and would increase particle stability without any significant effects on the critical properties of nanoparticles such as particle size and magnetization saturation value.

• 한국의학물리학회지:의학물리
• /
• 제25권4호
• /
• pp.205-209
• /
• 2014

의료기기에 사용되는 고분자제품은 주로 감마선 또는 전자 빔을 이용하여 살균을 하는데, 살균에 의해 재료특성이 변화한다. 카테터에 많이 사용되는 고분자 폴리머인 poly(ether-block-amides) (PEBA)는 살균에 의한 물성변화가 더욱 심하다고 알려져 있다. 따라서 본 연구에서는 살균 후 PEBA의 물성변화를 측정하여 전자선 살균이 미치는 영향에 대해 평가하였다. PEBA에 전자선을 조사하고 노화를 촉진시켜 유효기간 동안의 변화를 확인하였다. 급속노화가 이루어진 환경은 온도가 55도, 습도가 50%인 오븐에서 수행되었다. PEBA의 경도는 polyester 함량에 따라 달라지는데 본 연구에서 사용된 PEBA 시료의 경도는 35D (soft)부터 72D (hard)였다. 전자빔 살균에 의한 PEBA의 분자량 변화와 인장강도 변화를 측정 하였다. 측정결과, 노화로 인해 분자량이 현저히 감소함을 확인 하였다. 35D 시료의 경우 분자량이 54350 g/mol에서 39250 g/mol으로 감소하였다. 또한 전자 빔에 의해 살균된 PEBA의 인장 강도 및 신장율도 현저히 감소하였다. 35D PEBA시료의 인장강도 역시 28040 kPa에서 24118 kPa로 14% 이상 감소하였다. 결론적으로 전자선 빔으로 의료용으로 사용되는 PEBA제품을 살균할 경우 물성변화가 심각하게 발생하므로 전자 빔 살균은 문제가 많음을 알 수 있었다.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
• /
• pp.25-26
• /
• 2003

Electrically conducting polymers such as polypyrrole(PPy) or poly(3,4-ethylene dioxythiophene)(PEDOT) were sequentially polymerized chemically and electrochemically on various kinds of woven fabrics, giving rise to the fabrics with high electrical conductivity. The specific volume resistivity of the fabric prepared in this study was extremely low as 0.2 $\Omega$-cm. We figured out the electrically conducting fabrics were practically useful for many applications such as an EMI shielding material, a flexible surface heating element or a strain sensor for large deformation.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1998년도 가을 학술발표회논문집
• /
• pp.223-226
• /
• 1998

Polyvinylalcohol (PVA) is a crystalline polymer, capable of hydrogen bonding, which makes the polymer useful for many industrial applications. production of high strength fibers, medical substitutes, adhesives, and so on[1], Specially, among fiber-forming polymers, PVA has the second highest crystal modulus and extreme strength after polyethylene because the polymer chain can take a planar zig-zag conformation. (omitted)

• 공업화학
• /
• 제10권6호
• /
• pp.939-943
• /
• 1999

최근에 생분해성 고분자를 이용한 의료용재료로의 응용에 대한 관심이 고조되고 있다. 본 연구에서는 천연고분자(xanthan, locust bean, guar gum, chitosan 및 algin)를 생체재료로 사용할 목적으로 용액주조법에 의하여 분해성 필름을 제조하였다. 천연고분자로부터 제조한 생체재료의 가능성을 피부이식제로서 생체적합성 측정에 의하여 평가하였다. 이들을 실험동물의 등부위에 피하 삽입하여 필름의 시간에 따른 구조적, 중량적변화와 랫드의 혈액학적 변화를 측정하여 생체적합성을 연구하였다. 랫드에 대한 테스트결과 locust bean과 guar gum은 삽입 24시간, 48시간 후 조직에서의 생체 이물 반응에 의한 생체 부적합성을 나타내었으며, 일부 천연고분자로부터 제조한 분해성 필름은 단기간의 이상적인 생체재료로서의 가능성을 나타내었다.

• 대한의용생체공학회:의공학회지
• /
• 제28권2호
• /
• pp.244-249
• /
• 2007

Fluidic conditions for the separation of phases were surveyed in a microfluidic aqueous two-phase extraction system. The infusion ratio between polyethylene glycol (PEG) and dextran solution defines the concentrations of each polymer in micro-channel, which determine the phase-separation. The appropriate ratio between PEG (M.W. 8000, 10%, w/v) and dextran T500 (M.W. 500000, 5%, w/v) in order to perform the separation of phases of both polymers was observed as changing the mixed ratio of both polymers. Based on the fluidic conditions, stable two-phase solutions were obtained within 4% to 8% and 3% to 1% of PEG and dextran, respectively. In addition, the characteristics of the two-phase were discussed. The separation technique studied in the paper can be applied for the implementation of a lab-on-a chip which can detect various biological entities such cells, bacterium, and virus in an integrated manner using built in a biosensor inside the chip.