Microalgae produce not only lipids for biodiesel production but also valuable biochemicals which are often accumulated under cellular stress mediated by certain chemicals. While the microcarriers for the application of drug delivery systems for animal cells are widely studied, their applications into microalgal research or biorefinery are rarely investigated. Here we develope dual-functional magnetic microcapsules which work not only as flocculants for microalgal harvesting but also potentially as microcarriers for the controlled release of target chemicals stimulating microalgae to enhance the accumulation of valuable chemicals. Magnetic microcapsules are synthesized by layer-by-layer(LbL) coating of PSS-PDDA on Fe3O4 nanoparticle-embedded CaCO3 microparticles followed by removing CaCO3 sacrificial templates. The positively charged magnetic microcapsules flocculate microalgae by electrostatic interaction which are sequentially collected by the magnetophoretic separation. The microcapsules with a polycationic outer layer provide efficient binding sites for negatively charged microalgae and by that means are further utilized as a chemical-delivery and flocculation system for microalgal research and biorefineries.

Microcapsule membranes are fabricated with PLGA through double emulsion method and solvent evaporation method. In outer aqueous phase, surfactants such as PVA were replaced with metal salts as CaCl2 and MgCl2. Inside the microcapsule membrane, BSA was encapsulated as the model drug. Morphologies, BAS encapsulation efficiencies and BAS releasing behaviors are investigated. Through the process, microcapsule membranes with diameters of μm are generated and, through this work, we got a conclusion that the metal salts could be a good choice to replace PVA to solidify the microcapsule membrane surfaces.

With the development of marketing, time-temperature indicator (TTI) is applied to monitor the storage temperature and time to predict the shelf-life of food by irreversible color change. This study mainly focused on developing the solid-type enzymatic time temperature indicator as a first exploration on printable TTI. It was based on the phenomenon that starch would change its color into blue when meets iodine, and the hydrolysis of enzyme make the color turn to colorless gradually. Combining the microencapsulation technology to immobilize enzyme, several TTIs with different formulas were achieved, and hopefully to be applied on different foods, whose storage temperature is 4 and their shelf-life could be 5-6 days. Chilled pork meat was chosen as an indicating target to figure out a suitable specific TTI by activation energy comparing and lasting time matching.

Selenium was initially considered toxic to humans, but it was then discovered that selenium is essential for normal life processes. Selenium plays important roles in antioxidants. It is expected that chitosan microcapsules containing nano-selenium will be able to be used as a key material in bio-medical and cosmetic applications. The high concentration of chitosan derivatives guaranteesincreased antioxidative activity. Both inorganic and organic forms of selenium can be nutritional sources. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. The objective of this experiment was to study the antioxidative activity of chitosan nano-selenium. Our experiments were divided into five groups, in the presence of various concentrations(0.1%, 0.3%, 0.5%, 0.7%, and 0.9%) of chitosan. We performed an assessment of the antioxidant properties and cytotoxicity of respective concentrations of chitosan nano-selenium. The antioxidant activity was examined by the free radical scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl(DPPH) assay. The cytotoxicity effect was measured by means of 3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium bromide(MTT) assay. As a result, the electron donating abilities of 0.1%, 0.3%, 0.5%, 0.7%, and 0.9% of chitosan nano-selenium exhibited effective andioxidant scavenging activity at 12.5 ㎍/㎖ against DPPH radicals. 0.3% chitosan nano-selenium did not show cytotoxicity on human keratinocytes. In general, the cytotoxicity of 0.1% and 0.9% chitosan nano-selenium showed the lowest effects. Though low cytotoxicity of 0.5% and 0.7% chitosan nano-selenium exhibited 29.67% and 38.4% against human keratinocytes on adding 100 ㎍/㎖ and 50 ㎍/㎖, respectively, cell vitality was recovered with 200 ㎍/㎖. These findings support the notion that chitosan nano-selenium may be useful as a new active ingredient source for bioactive compounds.

A series of microcapsule were synthesized by using several PCM(Phase Change Material) as a core material and gelatin/arabic gum, melamine/formaldehyde as a shell material. Coacervation technique and in situ polymerization were adopted in synthesizing microcapsules. In the microencapsulation by coacervation, tetradecane and octadecane were used as core materials. In the microencapsulation by situ polymerization tetradecane, pentadecane, hexadecane, heptadecane, octadecane, and nonadecane were used as core material. The synthesized microcapsule was examined to observe the shape of the microcapsule. The particle size analysis was performed by particle size analyzer. The thermal properties(e.g. melting point, heat of melting, crystallization temperature, heat of crystallization, differences between melting point and crystallization temperature) were obtained by DSC(Differential Scanning Calorimeter). The stirring rate effect was investigated during the microencapsulation. It was found that with increasing the stirring rate much smaller microcapule was produced. However, this did not necessarily lead to formation of spherical microcapsule.

본 연구에서는 다당류와 단백질의 이온 결합으로 구성된 마이크로캡슐 및 에멀젼을 제조하여 다당류, 단백질의 비율에 따른 마이크로캡슐과 에멀젼의 안정도를 평가하였으며, 마이크로캡슐의 내부 오일도 종류별로 실험하였다. 에멀젼 입도를 줄여 안정도를 높여주기 위해 고압유화기를 이용하여 에멀젼을 제조하였으며 내부 담지 물질로 코엔자임 Q10 안정화를 관찰한 결과 대조군 대비 역가 하락이 없었다. 석유 유래 계면활성제가 아닌 천연 유래 원료만으로 안정한 마이크로캡슐 제조에 성공한 것이다. 광학현미경, 투과전자현미경을 이용하 여 마이크로캡슐 및 에멀젼의 물리적 안정도를 관찰하고 에멀젼의 구조분석을 하였으며, 입자의 표면전위 측정 을 통하여 pH 조절에 의해 제조되는 다당류/단백질 마이크로캡슐의 제조 메커니즘을 설명한다.

알로에 겔이 분산된 W/O 에멀젼을 감압 건조하는 방법으로 분산상의 수분을 제거하여 알로에 겔 마이크로캡슐을 제조하였다. 마이크로캡슐은 미네랄오일로 세척하고 재현탁시켜 유화제를 제거한 후에도 안정적인 현탁액으로 유지되었으며, 내부가 균일하게 채워진 직경 6.6 μm 이하인 구형 입자로 구성되어 있었다. 미네랄오일에 재현탁된 마이크로캡슐은 분율이 41% 이상에서 급격하게 점도가 증가하였고, 300 Pa 이상의 항복응력을 가진 전단유동화 특성을 나타내었으나, 틱소트로피는 뚜렷하게 관찰되지 않는 유변학적인 특성을 보였다. 오일에 현탁된 알로에 겔 마이크로캡슐의 분율이 높을수록 반고체의 특성이 증가하고 105 ℃에서 15 min 동안 가열하여도 에멀젼의 안정성이 유지됨을 경시적으로 관찰하였다. 따라서 알로에 겔 마이크로캡슐 현탁 크림을 기본 제형으로 다양한 종류의 알로에 겔 화장품의 개발이 가능할 것으로 예상된다.

불포화지방산의 함량이 많은 오징어 간유의 미세캡슐화 공정을 최적화하기 위하여 부형제 조성을 달리하여 미세캡슐화 특성을 살펴본 결과, 모든 조성비에서 유화액의 점도는 유사한 경향을 나타내었고, Na-caseinate의 함량이 높을수록 유화안정성이 증가하였다. 미세캡슐화 효율은 Na-caseinate와 cyclodextrin의 비율이 4:6 > 6:4 > 5:5 > 3:7 > 7:3의 순으로 4:6 비율이 가장 높게 나타났으나 미세캡슐화된 분말의 흡