Water-soluble Collagen Research Articles

An update review: several extraction methods for collagen isolation in vertebrate fish

Fish are vertebrate animals with a backbone that live in marine environments, presenting a potential source of collagen due to their high protein content. Collagen is a structural protein in the body's connective tissue, contributing 25 to 30% of the total body protein. Collagen sources in fish can be found in the skin, scales, and bones. The isolation of collagen from fish involves several stages, including separation and cleaning, size reduction, removal of non-collagenous components, collagen extraction, and precipitation. The extraction method utilized in collagen isolation impacts the quantity of collagen produced. The aim of this literature review is to identify extraction methods applicable for collagen isolation in vertebrate fish, serving as a reference for selecting extraction methods in future research. The updated review method involved collecting journal data from various literature sources, obtained from national and international journals discussing collagen extraction methods in vertebrate fish. Based on the update review, the isolation of collagen from vertebrate fish is carried out using several extraction methods, including acid soluble collagen extraction, pepsin soluble collagen, water soluble collagen, organic acid ultrasound-assisted, extrusion hydro extraction, deep eutectic solvent, and supercritical fluid extraction.

Effect of Acetic Acid Pretreatment on Hydro-extraction of Water-Soluble Collagen from Skin of Alaska Pollock (<I>Theragra chalcogramma</I>)

Highlight Research The optimal condition for production of water-soluble collagen from Alaska pollock fish skin was the pretreatment with 0.15 M acetic acid followed by hydro-extraction at 40oC with 150 rpm for two hours. Higher acetic acid concentration at a pretreatment step enhanced the higher yield of water-soluble collagen via hydro-extraction process. Hydro-extraction was an environmentally friendly method for converting Alaska pollock fish skin to water-soluble collagen. Alaska pollock fish skin could be used as an alternative source for collagen production. Abstract To date, there is no information on skin of Alaska Pollock (Theragra chalcogramma) being used as a source for collagen. In order to produce water-soluble collagen from the skin of Alaska Pollock, a process known as hydro-extraction is utilized. This technique does not need a long extraction time or a large amount of chemical reagent. The purpose of this study was to investigate the effect of acetic acid pretreatment on hydro-extraction of water-soluble collagen from Alaska Pollock skin. The skin samples were pretreated using acetic acid at different concentrations (0.01 M; 0.05 M; 0.1 M, 0.15 M) for two hours at chilling temperature. The pretreated skin samples were further processed to produce water-soluble collagen using the hydroxy-extraction method. The obtained collagen was analyzed for proximate compositions, yield, and amino acids compositions with high performance liquid chromatography. It was found that the proximate compositions of the collagen products, specifically the protein content (75%) and fat content (1%), met the requirements of the Indonesian National Standard (SNI 8076:2014). The collagen yield ranged from 2.6 to 3.13%. The predominate amino acids in collagen were glycine, arginine, proline, glutamic acid, serine, and alanine. Pretreatment of skin sample with 0.15 M acetic acid resulted in the highest yield of water-soluble collagen (3.13%) and protein content (91.13%). The skin of Alaska Pollock fish could be used as an alternative raw material to produce water-soluble collagen for medical, pharmacy or food processing applications.

Does Dietary Lipid Level Affect the Quality of Triploid Rainbow Trout and How Should It Be Assessed?

Organoleptic properties and nutritional value are the most important characteristics of fish fillet quality, which can be determined by a series of quality evaluation indexes and closely related to fish nutrition. Systematic organoleptic and nutritional quality evaluation indexes consisting of 139 indexes for physical properties and chemical compositions of triploid rainbow trout were established. Besides, effects of dietary lipid levels (6.6%, 14.8%, 22.8% and 29.4%) on the quality of triploid rainbow trout were analyzed in the study. The main results showed that, for fillet appearance quality, fish fed diets with lipid levels above 22.8% had higher fillet thickness and redness but lower gutted yield and fillet yield (p < 0.05). For fillet texture, fish fed the diet with a 6.6% lipid level had the highest fillet hardness (5.59 N) and lowest adhesiveness (1.98 mJ) (p < 0.05), which could be related to lipid, glycogen, water soluble protein and collagen contents of the fish fillet. For fillet odor, the odor intensity of “green, fatty and fishy” significantly increased with the increase of the dietary lipid level (from 1400 to 2773 ng/g muscle; p < 0.05), which was related to the degradation of n-6 and n-9 fatty acids. For fillet taste, a high lipid diet (≥22.8%) could increase the umami taste compounds contents (from 114 to 261 mg/100 g muscle) but decrease the bitterness and sourness taste compounds contents (from 127 to 106 mg/100 g muscle and from 1468 to 1075 mg/100 g muscle, respectively) (p < 0.05). For nutritional value, a high lipid diet could increase the lipid nutrition level (such as the content of long chain polyunsaturated fatty acids increased from 3.47 to 4.41 g/kg muscle) but decease tryptophan and selenium content (from 2.48 to 1.60 g/kg muscle and from 0.17 to 0.11 g/kg muscle, respectively). In total, a high lipid diet could improve the quality of triploid rainbow trout. The minimum dietary lipid level for triploid rainbow trout should be 22.8% to keep the better organoleptic and nutritional quality.

Asterias pectinifera-Derived Collagen Peptides Mixed with Halocynthia roretzi Extracts Exhibit Anti-Photoaging Activities during Exposure to UV Irradiation, and Antibacterial Properties.

Asterias pectinifera, a species of starfish and cause of concern in the aquaculture industry, was recently identified as a source of non-toxic and highly water-soluble collagen peptides. In this study, we investigated the antioxidant and anti-photoaging functions of compounds formulated using collagen peptides from extracts of Asterias pectinifera and Halocynthia roretzi (AH). Our results showed that AH compounds have various skin protective functions, including antioxidant effects, determined by measuring the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl radicals, as well as anti-melanogenic effects, determined by measuring tyrosinase inhibition activity. To determine whether ethosome-encapsulated AH compounds (E(AH)) exert ultraviolet (UV)-protective effects, human dermal fibroblasts or keratinocytes were incubated with E(AH) before and after exposure to UVA or UVB. E(AH) treatment led to inhibition of photoaging-induced secretion of matrix metalloproteinase-1 and interleukin-6 and -8, which are associated with inflammatory responses during UV irradiation. Finally, the antibacterial effects of AH and E(AH) were confirmed against both gram-negative and gram-positive bacteria. Our results indicate that E(AH) has the potential for use in the development of cosmetics with a range of skin protective functions.

Novel Modification of Collagen: Realizing Desired Water Solubility and Thermostability in a Conflict-Free Way.

Because of poor water solubility and low thermostability, the application of collagen is limited seriously in fields such as injectable biomaterials and cosmetics. In order to overcome the two drawbacks simultaneously, a novel bifunctional modifier based on the esterification of polyacrylic acid (PAA) with N-hydroxysuccinimide (NHS) was prepared. The esterification degree of PAA-NHS esters was increased upon increasing the NHS dose, which was confirmed by Fourier-transform infrared (FTIR) and nuclear magnetic resonance spectrascopy. FTIR results indicated that the triple helix of the modified collagens remained integrated, whereas the molecular weight became larger, as reflected by the sodium dodecyl sulfate–polyacrylamide gel electrophoresis pattern. The modified collagens displayed excellent water solubility under neutral condition, owing to lower isoelectric point (3.1–4.3) than that of native collagen (7.1). Meanwhile, denaturation temperatures of the modified collagens were increased by 4.8–5.9 °C after modification. The modified collagen displayed hierarchical microstructures, as reflected by field-emission scanning electron microscopy, while atomic force microscopy further revealed a “fishing net-like” network in the nanoscale, reflecting a unique aggregation behavior of collagen macromolecules after modification. As a whole, the PAA-NHS ester as a bifunctional modifier endowed collagen with desired water solubility and thermostability in a conflict-free manner, which was beneficial to the process and application of the water-soluble collagen.

Collagen Isolation from Arctic Marine Organisms and Their Industrial Processing Wastes

The results of the isolation of collagen hydrolysates from tissues of two Arctic marine organisms are presented. Extraction and use of marine organism collagen is a part of complex waste less processing of sea catches. Possible ways of preparing water-soluble collagen hydrolysates from different sources were studied. It is established that for preparing soluble collagen hydrolysate from skin of cod Gadus morhua acid hydrolysis in 0.3% acetic acid is suitable. Purification of solution by means of ultrafiltration gives a pure collagen hydrolysate with mass fraction of the main substance about 98%. Collagen of muscular skin bag of holothuria Molpadia borealis is almost insoluble in acid and alkali solutions. The major mass of collagen remains in an insoluble residue. The analysis of infrared spectrum transmission and chemical analysis of the general carbohydrates and collagen in different fractions showed that as a result of acid and alkaline processing of raw materials the glycosaminoglycans (GAG) and some quantity of collagen are extracted, their main quantity was determined in alkaline extracts. For extraction of soluble collagen from insoluble residue it is required enzymatic by pepsin in acidic medium. Properties of holothurian collagen and fish collagen are different. The preparation of water-soluble collagen derivatives requires using enzymatic hydrolysis.

Dual-functionalized hyaluronic acid as a facile modifier to prepare polyanionic collagen

Hyaluronic acid (HA) is a natural polysaccharide possesses outstanding physiological activities. In this work, HA was activated as a novel collagen modifier via the esterification reaction between N-hydroxysuccinimide (NHS) and the carboxyl groups of HA. Both of Fourier transform infrared spectroscopy (FTIR) and 1H- nuclear magnetic resonance (NMR) spectra indicated the successful synthesis of HA-NHS esters. As reflected by FTIR, circular dichroism (CD) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), collagens modified with HA-NHS ester maintained its intact triplex structure with larger molecular weight. The resultant polyanionic collagen displayed an excellent dissolubility in the neutral water to form a clear solution, due to the significantly lower isoelectric point values (3.8–4.4) compared with that of the native collagen (7.1). In addition, the thermal transition temperature of collagen was significantly increased (16 °C) after modifying with HA-NHS esters. Both of the aggregation morphology and rheological property exhibited high dependence on the NHS/COOH ratio of HA-NHS esters, as reflected by field-emission scanning electron microscopy (FESEM) and rheological test, respectively. The present study offered a novel dual-functional modifier based on the design of HA-NHS ester to obtain water-soluble collagen with desired thermal stability and rheological property, which will significantly widen the application range of collagen, especially in the fields of injectable biodegradable materials and cosmetics.

Fluorescence studies on the aggregation behaviors of collagen modified with NHS-activated poly(γ-glutamic acid)

The poly(γ-glutamic acid)-NHS (γ-PGA-NHS) esters were used to endow collagen with both of excellent water-solubility and thermal stability via cross-linking reaction between γ-PGA-NHS and collagen. In the present work, the effect of γ-PGA-NHS on the aggregation of collagen molecules was studied by fluorescence techniques. The fluorescence emission spectra of pyrene in collagen solutions and the intrinsic fluorescence emission spectra of collagen suggested different effects of γ-PGA-NHS on collagen molecules: inhibiting aggregation below critical aggregation concentration (CAC) and promoting aggregation above CAC. The two-dimensional (2D) fluorescence correlation spectra indicated that the intermolecular hydrogen bonding and cross-linking between γ-PGA-NHS and collagen would influence the aggregation of collagen molecules. By the ultra-sensitive differential scanning calorimeter (VP-DSC), it was found that the main denaturational transition temperature (Tm2) of modified collagen increased, while its calorimetric enthalpy changes (ΔH2) decreased compared to those of native collagen, further indicating that the modification of γ-PGA-NHS influenced the aggregation of collagen molecules. The study provide useful information for the utilizing and or the processing of water-soluble collagen in aqueous solution in the fields such as cosmetics, health care products, tissue engineering and biomedical materials, etc.

The effect of water vapor pressure on muscle collagen solubility and selected characteristics of the longissimus lumborum muscle in crossbred cattle

Abstract Most scientific studies are dedicated to the possibility of preparing beef for consumption under industrial conditions. Few publications are devoted to the issue of collagen thermohydrolysis in conditions available to the consumer. This study has analyzed the effect of small values of water vapor pressure on major culinary indices and chemical components of the longissimus lumborum muscle obtained from bulls with different growth rates. The experiment involved 48 animals. On the basis of the gain during the fattening time, the animals were divided into a low growth intensity group, with a daily body weight gain of ≤900 g, and a high growth intensity group with a daily gain of &gt;900 g/day. A part of the samples of the longissimus lumborum muscle (control) was thermally treated in a water bath at 75°C. Another part was heat treated in a pressure-pot at 150°C, at a pressure of 0.1 MPa. The next part of samples was subjected to the same temperature, but the pressure was 0.2 MPa. The obtained results indicate that the values of the studied indices were largely affected by thermal processing parameters rather than the animals’ growth rate. The highest contents of total protein and water-soluble collagen were obtained in the case of a temperature of 150°C and the highest pressure (0.2 MPa). Water vapor with increased temperature and pressure also created favorable conditions for obtaining better meat tenderness and more favorable values of the water holding capacity. The latter characteristic appeared to be strongly connected with an increasing amount of water-soluble collagen, which was confirmed by relatively high values of the correlation coefficient between these characteristics. A strong positive correlation was also shown between thermal drip and the total collagen content in meat.

A novel strategy to fabricate water-soluble collagen using poly(γ-glutamic acid)-derivatives as dual-functional modifier

Native collagen cannot be dissolved in neutral pH buffer, limiting its application in many fields. The traditional method to prepare water-soluble collagen is succinylation modification, which causes the decrease in the thermal stability. Therefore, poly(γ-glutamic acid)-N-hydroxysuccinimide (γ-PGA-NHS) esters were used as a novel modifying agent of collagen. FTIR results indicated the intact retention of native triple-helix structure after modification. Isoelectric point of the modified collagens shifted continuously to lower values with increasing the γ-PGA-NHS/collagen ratios (w/w). Consequently, the modified collagen can form a clear solution in neutral pH buffer. Furthermore, the denaturation temperature (Td) of the modified collagens reached 44.8–49.9°C, which were 6.0–11.1°C higher than that of native collagen. However, it should be noted that gelation occurred when modifier/collagen ratio (w/w)=50% as γ-PGA-NHS with a relatively high esterification degree was used. As a whole, these results indicated that dual-functional modification in regards to both of water solubility and thermal stability on collagen can be achieved using γ-PGA-NHS esters with a relatively low esterification degree. In addition, the proliferation of fibroblasts could be promoted as reflected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and 4′,6-diamidino-2-phenylindole (DAPI) method, suggesting the excellent cytocompatibility of the modified collagens. The present study provided useful information to the design of novel water-soluble collagen, which could be applied in the fields including biomaterials, cosmetics etc.

Production of low molecular collagen peptides-loaded liposomes using different charged lipids

To encapsulate water soluble collagen peptides, liposomes loaded with peptides were assembled using a combination of thin film hydration and ultrasonication emulsification techniques. The influence of lipid charge, duration and power of ultrasonication, and collagen peptide concentration were evaluated. Layered liposomes loaded with collagen peptides, charged lipids, chitosan (+) or low-methoxyl pectin (−) were produced using the layer-by-layer electrostatic deposition method. For the liposomes loaded with collagen peptides, the most efficient and dependable manufacturing method was variation of the ultrasonication duration, which was capable of producing smaller sizes (through increasing ultrasonication duration) and liposomes loaded with peptides with >60% encapsulation efficiency. For layered liposomes loaded with collagen peptides, charged lipids were determined to be more effective in the production of smaller liposomes than charged biopolymers. In addition, layered and non-layered liposomes loaded with peptides with a particle size <100nm were physically stable during storage, regardless of storage temperature and time.

The influence of diet on collagen content and quality attributes of infraspinatus muscle from Holstein–Friesian young bulls

The aim of the study was to determine effects of feeding intensity on collagen content and eating quality of infraspinatus (INF) muscle. Twenty Polish Holstein-Friesian bulls (11-month-old) were fed either intensively (I, n=10, with triticale meal addition to total mixed ration) or semi-intensively (SI, n=10, without triticale meal) before slaughter at 19months. The animals from I group showed higher body weight at the end of fattening, average daily gain and dressing percentage than SI group. The INF muscle from I treatment had higher fat content and the proportion of water-soluble collagen, whereas lower insoluble collagen content compared with SI treatment. There were no differences in shear force values, cooking loss and eating quality between the treatments. In conclusion, feeding Holstein-Friesian bulls with increased energy value fodder beneficially affected its slaughter value and collagen profile in infraspinatus muscle.

The influence of crossbreeding on collagen solubility and tenderness of Infraspinatus and Semimembranosus muscles of semi-intensively reared young bulls.

The aim of the present study was to investigate the effects of crossbreeding on collagen content and solubility, shear force (WBSF) and the eating quality of Infraspinatus (INF) and Semimembranosus (SM) muscles of young bulls and the relationships between collagen content and solubility, shear force and the eating quality of beef. The experimental material comprised muscles of crossbred young bulls (about 600 days old) of Polish Holstein-Friesian (PHF) × Limousine (LM) (n = 10), PHF × Charolaise (CH) (n = 9), PHF × Hereford (HER) (n = 9) breeds. The crossbreeding influenced WBSF, aroma and taste, total, water-soluble, acid-soluble, total soluble and insoluble collagen content, as well as the acid-soluble, total soluble and insoluble collagen proportions. WBSF was significantly negatively correlated with sensorial tenderness and water-soluble collagen content. The eating quality of beef obtained from different crossbreds was similar; however, the meat from PHF × LM and PHF × HER bulls had lower WBSF values than PHF × CH bulls. © 2016 Japanese Society of Animal Science.

Study of interaction between water-soluble collagen and carboxymethyl cellulose in neutral aqueous solution

The interactions of succinylated collagen (SC) and carboxymethyl cellulose (CMC) in neutral solutions (pH∼6.9) were investigated, which could provide information for the fields of tissue engineering and cosmetics. According to the results from viscometric measurements, the SC and CMC molecules were possibly compatible as CMC≤50%. Ultrasensitive microcalorimetry reflected the increase in the values of transition temperature (Tm) and heat capacity change (ΔCp) as CMC≤50%, while both of them decreased as the CMC content further increased. Two-dimensional Fourier transform infrared spectroscopy analysis confirmed the hydrogen bonding and electrostatic interactions between SC and CMC, and the hydrogen bonding interaction played a key role as CMC≤50%, while electrostatic interaction became predominant as more CMC was added. Atomic force morphology revealed the changes in the aggregation of SC induced by the addition of CMC.

Water holding capacity and collagen profile of bovine m. infraspinatus during postmortem ageing

Changes in the water holding capacity (WHC) and collagen profile in bovine m. infraspinatus during ageing in a vacuum at 3°C up to 20days were studied. Moisture, expressible water and total collagen content were determined in raw samples and muscles were then subjected to thermal treatment in steam. Moisture, collagen fractions (total, water-soluble, insoluble, acetic acid-soluble, total soluble) and cooking loss were determined in the cooked meat. Ageing time did not significantly influence WHC (expressible water content as a % of moisture), moisture content in raw and cooked meat or cooking loss. Between the 5th and 10th day of ageing a significant increase was noted in acetic acid-soluble collagen and total soluble collagen content along with a decrease in insoluble collagen content (p<0.05). A significant negative relationship was found between the expressible water content and the water-soluble collagen. It was concluded that connective tissue ageing of bovine m. infraspinatus might be finished after 10days.

Preparation of PCL/silk fibroin/collagen electrospun fiber for urethral reconstruction

To prepare polycaprolactone (PCL)/silk fibroin/collagen electrospun nanofiber scaffold and test its effects on growth and proliferation of oral mucosal epithelial cells. Regenerated silk fibroin film, water-soluble collagen powder, and PCL, at mass ratios of 1:1:4, 1:1:8, and 1:1:10, were dissolved in hexafluoroisopropanol, and electrostatic spinning method was adopted to prepare PCL/silk fibroin/collagen electrospun nanofiber scaffold. In vitro cultured oral mucosal epithelial cells were inoculated on the material surface, MTT assay and scanning electron microscopy were adopted to study the growth and proliferation of oral mucosal epithelial cells on the material surface, and cell compatibility of PCL/silk fibroin/collagen electrospun nanofiber was evaluated. The result of MTT assay showed that oral mucosal epithelial cells were growing well on the PCL/silk fibroin/collagen electrospun nanofiber scaffold. Scanning electron microscopy showed that the prepared electrospun fiber was uniform in diameter and presented an interconnected porous net structure, and oral mucosal epithelial cells had a good growth form on the surface of the modified material. PCL/silk fibroin/collagen electrospun nanofiber scaffold has appropriate pore size and porosity, is suitable for the growth of oral mucosal epithelial cells, has good cell compatibility, and is a good scaffold for tissue engineering urethral reconstruction.

Effect of gender on collagen profile and tenderness of infraspinatus and semimembranosus muscles of Polish Holstein-Friesian x Limousine crossbred cattle

The aim of the study was to evaluate the effect of gender of young Polish Holstein-Friesian x Limousine crossbred cattle on collagen profile, tenderness and sensorial quality of infraspinatus (INF) and semimembranosus (SEM) muscles. The experiment was carried out using bulls (n=8), steers (n=8) and heifers (n=8) produced in a semi-intensive system. Bulls and steers showed higher body weight at the end of fattening than heifers (P<0.01). The animal gender did not influence cooking loss of muscles and shear force values of SEM roasts, whereas bulls INF muscles had lower (P<0.01) shear force values than heifers and steers. Bulls had a higher amount of total and insoluble collagen and a lower amount of total soluble collagen than steers. Water soluble collagen in INF muscle was higher for bulls than heifers and steers, whereas acid soluble collagen was lower for bulls than for steers and heifers. Animal gender did not influence any of the sensorial attributes of SEM muscle. INF muscles from bulls were scored higher for tenderness, juiciness and overall acceptability (P<0.01, P<0.05 and P<0.05, respectively) than heifers. Since roasts prepared from meat originated from young bulls, heifers and steers of the Polish Holstein-Friesian x Limousine crossbreed were highly scored, it can be concluded that the crossbreed can be used to produce culinary beef of high eating quality.

Transglutaminase-catalyzed grafting collagen on chitosan and its characterization

Collagen grafted chitosan was prepared with microbial transglutaminase (MTGase) as biocatalyst which showed high efficiency, selectivity, mild reaction condition and environmental friendliness. The reaction conditions that influenced the degree of substitution (DS) were optimized, which included the reaction time, the reaction temperature, the mass ratio of collagen to chitosan and the mass ratio of MTGase to chitosan. In this study, the water-solubility collagen–chitosan could serve not only to reduce the loss of moisture but also to absorb the moisture. And the moisture absorption and moisture retention abilities were closely related to the DS values. In addition, in vitro antioxidant activity was evaluated in terms of DS values and concentration. Furthermore, L929 mouse fibroblasts were cultured with collagen–chitosan, and methylthiazol tetrazolium (MTT) assay exhibited that collagen–chitosan with DS of 0.660 displayed pronounced cell viability at 2.5mg/ml. Therefore, the water-soluble collagen–chitosan showed the potentiality to repair skin in cosmetic, biomedical and pharmaceutical fields.

콜라겐 수용액을 함유하는 역미셀의 제조 및 립 제품에 응용

립스틱의 보습력을 개선하기 위해 수용성 콜라겐(30 wt%)을 역미셀 방법으로 립스틱의 유상 내에 포접하였다. 콜라겐을 포함하는 역미셀은 외부상으로서 caprylic/capric triglyceride와 계면활성제인 polyoxyethylene(10) octylphenyl ether (Triton X-100)와 보조계면활성제로 aliphatic alcohol인 1-dodecanol을 이용하여 제조되었다. 콜라겐을 포접하는 역미셀의 형성 조건은 전기전도도와 methylene blue (MB)를 이용한 UV-vis spectrum을 통해 확인하였고, 콜라겐 포접체를 함유하는 역미셀의 립스틱에서 안정성 및 보습력은 레올로지 측정, 수분량 측정 및 아미노산 정량을 통해 확인하였다. 물과 계면활성제의 농도비인 W (water-pool), [<TEX>$H_2O$</TEX>]/[Triton X-100]는 10이하에서 안정한 역미셀이 형성되었다. 20 wt%의 콜라겐 포접 역미셀을 함유한 립스틱은 역미셀을 함유하지 않은 립스틱과 경도에서 큰 차이없이 안정하였으며, 수분량은 59%까지 개선되었고, 아미노산 함량은 92.7%였다. Water-soluble collagen (30 wt%) was entrapped within oil phase of lipstick using reversed micelle method to improve the moisture capacity of the lipstick. Reversed micelles containing collagen were prepared using caprylic/capric triglyceride as external phase and polyoxyethylene (10) octylphenyl ether (Triton X-100) and 1-dodecanol as surfactant and co-surfactant, respectively. The formation of reversed micelle encapsulating collagen was confirmed by measuring electric conductivity and UV-vis spectrum using methylene blue (MB). The stability and moisture capacity of the lipstick containing 20 wt% collagen encapsulated reversed micelles were observed by measuring rheology property, moisture content and amino acid content. The molecular ratio (W, water-pool) of water to surfactant (Triton X-100) in the most stable reversed micelle was <TEX>${\leq}$</TEX> 10. The hardness of the lipstick had no difference with that of the lipstick without reversed micelle, and the moisture content was increased to 59% and the amino acid content was 92.7%.

Preparation of N, O-carboxymethyl chitosan-Human-Like Collagen Microspheres for Drug Delivery

In this investigation, the N, O-carboxymethyl chitosan (NOCC) was synthesized. A novel pH-sensitive hydrogel system composed of a water-soluble chitosan derivative (N,O-carboxymethyl chitosan, NOCC)and Human-like collagen (HLC) blended with phosphate was developed for controlling drug delivery and NOCC–HLC microspheres were prepared by the technology of electrostatic droplet generation technique. The release profiles of a model protein drug (bovine serum albumin, BSA) from test hydrogels were studied in simulated gastric and intestinal media.