• 대한의용생체공학회:의공학회지
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• 제43권4호
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• pp.251-258
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• 2022

Silk fibroin microparticles were fabricated using a phase separation technique between silk fibroin solution and polyvinyl alcohol. We found that the concentration of polyvinyl alcohol determines the size of microparticles. The mean diameter of the silk fibroin microparticles varied from 3.48 ㎛ to 4.05 ㎛. The silk fibroin microparticle size increased as a function of the concentration of PVA in aqueous silk solution. The resulting silk fibroin microparticles have narrow size distribution (i.e. monodisperse) and smooth/spherical surface. Also, we studied the effects of mouse serum, sodium phosphate buffer (PBS), and pH on the stability of the silk fibroin microparticles. Overall, we demonstrated the simple method to fabricate and to control the silk fibroin microparticles that makes our silk microparticles to be usable for a potential drug delivery carrier.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1784-1788
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• 2014

The present study suggests a novel method to produce raspberry-like microparticles containing diverse functional materials inside. The raspberry-like microparticles were produced from a random assembly of uniformly-sized poly(methyl methacrylate) (PMMA) nanoparticles via electrospraying. The solution containing the PMMA nanoparticles were supplied through the inner nozzle and compressed air was emitted through the outer nozzle. The air supply helped fast evaporation of acetone, so it enabled copious amount of microparticles as dry powder. The microparticles were highly porous both on the surface and interiors, hence various materials with a function of UV-blocking ($TiO_2$ nanoparticles and methoxyphenyl triazine) or anti-aging (ethyl(4-(2,3-dihydro-1H-indene-5-carboxyamido) benzoate)) were loaded in large amount (17 wt % versus PMMA). The surface and interior structures of the microparticles were dependent on the characteristics of functional materials. The results clearly suggest that the process to prepare the raspberry-like microparticles can be an excellent approach to generate functional microstructures.

• 대한약침학회지
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• 제19권4호
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• pp.303-311
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• 2016

Objectives: Allergic asthma generally presents with symptoms of wheezing, coughing, breathlessness, and airway inflammation. Seonpyejeongcheon-tang (SJT) consists of 12 herbs. It originated from Jeong-cheon-tang (JT), also known as Ding-chuan-tang, composed of 7 herbs, in She-sheng-zhong-miao-fang. This study aimed to evaluate the effects of local delivery of SJT via inhalable microparticles in an asthma mouse model. Methods: Microparticles containing SJT were produced by spray-drying with leucine as an excipient. SJT microparticles were evaluated with respect to their aerodynamic properties, in vitro cytotoxicity, in vivo toxicity, and therapeutic effects on ovalbumin (OVA)-induced asthma in comparison with orally-administered SJT. Results: SJT microparticles provided desirable aerodynamic properties (fine particle fraction of $48.9%{\pm}6.4%$ and mass median aerodynamic diameter of $3.7{\pm}0.3{\mu}m$). SJT microparticles did not show any cytotoxicity against RAW 264.7 macrophages at concentrations of 0.01 - 3 mg/mL. Inhaled SJT microparticles decreased the levels of IL-4, IL-5, IL-13, IL-17A, eotaxin and OVA-IgE in bronchoalveolar lavage fluid (BALF) in mice with OVA-induced asthma. These effects were verified by histological evaluation of the levels of infiltration of inflammatory cells and collagen, destructions of alveoli and bronchioles, and hyperplasia of goblet cells in lung tissues. The effects of SJT microparticles in the asthma model were equivalent to those of orally-administered SJT extract. Conclusion: This study suggests that SJT is a promising agent for inhalation therapy for patients with asthma.

• KSBB Journal
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• 제27권4호
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• pp.237-242
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• 2012

In this study, zein microparticles and drug-loaded zein microparticles were prepared using supercritical ASES technique. The effects of operating parameters on particle size and morphology were investigated. ASES-processed zein microparticles consisted of agglomerates of very fine unit particles. As temperature increased, the size of unit particles increased and their morphology became more spherical. The addition of water to the solvents for zein resulted in the formation of more spherical microparticles. The release characteristics of drug-loaded zein microparticles were also studied.

• 폴리머
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• 제35권5호
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• pp.424-430
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• 2011

Biodegradable poly[(glycine ethyl ester)-(phenylalanine ethyl ester) phosphazene](PGPP) microparticles were fabricated by electrohydrodynamic atomization to apply drug release test. Atomization parameters such as applied voltage, polymer concentration, and molecular weight were investigated to inspect their effects on the size and morphology of microparticles. The average diameter of PGPP microparticles decreased as increasing applied voltage and solution flow rate. Dichloromethane/dioxane mixture shows better results for the preparation of microparticles than single solvent owing to the different PGPP solubility in solvent. Blending PGPP polymers with proper molecular weights not only favored the production of spherical PGPP microparticles via electrohydrodynamic atomization, but also provided a way to adjust drug (rifampicin) release behavior. Drug-loaded biodegradable polyphosphazene microspheres can be fabricated via electrohydrodynamic atomization, which has potential use in biomedical applications.

• 한국식품과학회지
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• 제44권2호
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• pp.191-195
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• 2012

아민화 젤라틴 미세캡슐은 젤라틴의 양이온인 amino 그룹과 후코이단의 음이온인 sulfate 그룹과의 이온결합으로 제조되었다. 후코이단의 농도가 증가할수록 미세캡슐의 유리아미노 그룹의 함량은 감소했으며, 또한 미세캡슐로부터의 방출 속도 역시 후코이단의 농도가 증가함에 따라 감소했고 pH 1.2인 인공위액에서의 방출 속도가 pH 7.4인 PBS 에서보다 더 빠른 것을 알 수 있었다. 아민화 젤라틴 미세캡슐은 일반 젤라틴 미세캡슐보다 유리 아미노 그룹의 함량이 높아 음전하를 띄고 있는 위점막에 점착력이 커짐을 알 수 있었다. 본 연구는 아민화 젤라틴 미세캡슐을 제조하고 점착력을 살펴본 것으로서, 본 연구결과를 토대로 amoxicillin을 캡슐화한 아민화 젤라틴 미세캡슐의 헬리코박터 저해능력에 대한 연구도 진행되어야 할 것이다.

• Archives of Pharmacal Research
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• 제29권8호
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• pp.707-711
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• 2006

Bifidobacteria-loaded alginate poly-l-lysine microparticles (bap microparticles) were prepared using an air atomization method and then freeze-dried. The viability of the bap microparticles was investigated as a function of the amount of the bifidobacteria cultures, and the addition of a yeast extract, cryoprotectants, antioxidants and neutralizer. The size of the bap microparticles with and without the bifidobacteria was $84.8{\pm}28.5\;{\mu}m$ ($mean{\pm}standard$ deviation) and $113.1{\pm}38.5\;{\mu}m$, respectively. The surface morphology was slightly ellipsoid and wrinkled regardless of the incorporating bifidobacteria. The viability gradually decreased with increasing freeze-drying time. Free-flowing powdered bap microparticles were obtained at least 12 h after freeze-drying the wetted slurry of bap microparticles. However, the particles tended to aggregate when either lactose or ascorbic acid was added. The addition of a yeast extract, cryoprotectants (glycerol and lactose), antioxidants ($NaHSO_3$ and ascorbic acid) and neutralizer $(Mg_3(PO_4)_2)$ resulted in a significantly higher viability of the bifidobacteria in the bap microparticles after freeze-drying (0.34-1.84 log) compared with the culture alone.

• 한국식품과학회지
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• 제35권5호
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• pp.835-840
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• 2003

Hexane/aerosol OT(AOT)/물로 구성된 역미셀의 water pool내에서 알긴산나트륨과 염화칼슘의 반응성을 이용하여 알긴산 조미세입자의 제조를 시도하였다. 주사전자현미경(SEM) 관측결과 미세한 입자들이 형성됨을 확인하였으며 이는 알긴산나트륨 함유 water pool과 염화칼슘 함유 water pool이 상호 접촉에 의해 내부물질의 교환이 가능함을 의미한다. 역미셀의 water pool 크기에 영향을 주는 유화제(AOT)에 대한 물의 몰농도 비율인 Wo 값을 5에서 10으로 증가함에 따라 미세입자의 크기가 유의적으로 증가하였으며 제조된 미세입자간의 입도특성을 비교한 결과, 각 입자의 표면적, 최장식경(max diameter), 최단직경(min diameter), 평균직경(mean diameter). 그리고 각 입자의 둘레 길이는 Wo 값이 증가함에 따라 유의적으로 증가하였다(p<0.05). Wo 값이 15 이상에서는 입자간 응집이 발생하였으며 Wo 값이 20인 경우에는 안정한 역미셀의 형성이 불가능하였다. 제조된 입자의 평균직경은 Wo=5에서 $2.08\;{\mu}m$이었으며 10인 경우 $2.66\;{\mu}m$으로 나타났으며 이는 기존에 보고 된 알긴산 입자의 크기에 비하여 약 $70{\sim}1000$배 가량 작은 수준이었다. 한편, 입자의 구형도는 분석된 Wo 구간에서 유의적인 자이를 보이지 않음으로써 역미셀에 의해 형성되는 입자의 외부형태는 안정한 역미셀을 형성하는 Wo 구간에서는 크게 변화하지 않는 것으로 판단된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.476-481
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• 2004

The aim of this study was to formulate a sustained release system for indomethacin (IND) with rosin gum obtained from a pine tree. Rosin microparticles were prepared by a disper­sion and dialysis method without the addition of surfactant. In order to investigate the influence of solvents on the formation of colloidal microparitcles, various solvents like ethanol, DMF, DMAc, and acetone were used. The rosin microparticles containing IND were characterized by X­ray differactometry (XRD) and differential scanning calorimetry (DSC). The morphologies of rosin microparticles observed by scanning electron microscopy (SEM) were spherical. The solvents used to dissolve rosin significantly affected the drug content and drug release rate of IND. The release behaviors of IND from the rosin microparticles were dependent on the drug content and size of the particles. Rosin micorparticles with a higher drug content and of a larger particle size had a slower drug release rate. Also, the IND release rate from the rosin microparticles could be regulated by the rosin content in the microparticles. From these results, rosin microparticles have the potential of being used as a sustained release system of IND.

• Journal of Pharmaceutical Investigation
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• 제39권1호
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• pp.59-63
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• 2009

Soybean phosphatidylcholine microparticles loaded with cyclosporin A (CsA) were prepared by the modified emulsion solvent diffusion and ionic gelation method, in which chitosan on the surface of the microparticles was crosslinked with various concentrations of tripolyphosphate (TPP). The morphology of the particles was characterized by scanning electron microscopy (SEM). The change of particle size and zeta-potential by chitosan on the surface of the lipid microparticles were systematically observed. The encapsulation efficiency and loading capacity of CsA in the particles were determined by high performance liquid chromatography (HPLC). In vitro release kinetics was studied using the dialysis method. In the results, the mean particle size and the zeta-potential of lipid microparticles increased when the attached chitosan was cross-linked (from 2.5 to 6.2 ${\mu}m$ and from -37.0 to +93.0 mV, respectively). The cyclosporin A-loaded lipid microparticles appeared discrete and spherical particles with smooth surfaces. The encapsulation efficiency of CsA was between 79% and 90% while the loading capacity was between 41% and 56%. In vitro release study showed that the crosslinkage of chitosan by TPP significantly delayed the release of CsA from the particles in a concentration-dependent manner. Thus, the release of CsA from the lipid microparticles could be controlled by tripolyphosphate used as a cross-linking agent.