Pretreatment Of Skin Research Articles

Produksi Ekstrak Bioaktif Untuk Aditif Pangan Dari Limbah Kulit Buah Naga: Pengaruh Metode Pre-Treatment Dan Ekstraksi

Dragon fruit is one of the tropical fruits can be grown in Indonesia. The skin of dragon fruit, which is accounted for 30-35% of the whole fruit usually thrown away as waste. This study aims to produce a bioactive extract from extraction of dragon fruit skin that is rich in phenolic and pigment compounds then it used as food additives. The variation that was used in this study includes the application of drying as pre-treatment of dragon fruit skin and the extraction methods (maceration and Soxhlet extraction). The obtained extracts were evaluated for the amount of total phenolic compounds and pigments (anthocyanin and betacyanin). Drying of dragon fruit skin was found to yield lower amounts of bioactive materials, which may occur due to the thermal degradation even though a low drying temperature was used. In addition, the maceration method was found to give a higher amount of bioactive materials compared with the Soxhlet method. The extraction with the highest yield of bioactive materials was obtained by the use of fresh dragon fruit skin and maceration for 240 minutes, which gave amounts of anthocyanin, betacyanin, and total phenolic compounds of 0.08, 0.04, dan 0.35 mg/g fresh dragon fruit skin, respectively.

Matrix Metalloproteinase 9 (MMP9) Inhibitor Prevents Mustard Induced Microvesication and Promotes Cutaneous Wound Healing

Skin exposure to the chemical warfare agent, sulfur mustard (bis‐2‐chloroethylsulfide, SM), is characterized by severe blister formation and a prolonged inflammatory response. The mechanisms of these SM toxic effects are still poorly defined, and effective medical countermeasures against SM‐induced cutaneous injury have yet to be established. Animal models demonstrate disruption of the skin architecture at the dermal‐epidermal junction (DEJ) when exposed to the vesicant, SM; the damage may be further exacerbated by overexpression of MMP9. Studies show MMP9 degrades basement membrane (BM) components and regulates inflammation in tissue injuries; inhibition of MMP9 suppresses inflammation and promotes wound repairs in tumors and various wound models. In the present studies, ([N‐hydroxy‐3‐phenyl‐2‐(4‐phenylbenzenesulfonamido) propanamide], BiPS), a specific MMP9 inhibitor, was evaluated for its ability to prevent microvesication, suppress inflammation, and promote wound healing following SM exposure using the mouse ear vesicant model. Treatment of male CD1 mouse ear skin with SM (0.08 mg) caused a characteristic SM induced injury including edema, inflammatory cell infiltration, and the formation of microvesicles at the DEJ. Expression of MMP9 mRNA and protein in the skin progressively increased with time 24–168 h following SM exposure. Immunofluorescence studies showed disruption of the BM molecule type IV collagen (COL4), increased expression of inflammation marker, COX2, and upregulation of the skin wound marker keratin 6 (K6) in SM induced skin wounds. SM also caused macrophage (F4/80) accumulation in the tissue which persisted up to 168 h post exposure. Pretreatment of ear skin with BiPS significantly reduced SM‐induced dermal edema and maintained the integrity of the DEJ‐BM as evidenced by contiguous expression of COL4. At 168 h post SM exposure, mRNA and protein expression of MMP9 was significantly downregulated in BiPS treated mice. BiPS treatment also reduced the number of macrophages accumulating in the tissue, and suppressed expression of COX2, and downregulated expression of K6. Taken together, these data indicate that BiPS treatment was able to suppress both inflammation and degradation of BM zone in skin due to SM. This compound was effective in targeting MMP9 to protect against SM induced microvesication and promote wound repairs. MMP9 inhibitors may be useful as medical countermeasure against SM‐induced cutaneous injury.Support or Funding InformationSupported by NIH grants ES005022 and AR055073.

Обоснование возможности использования кожи ската (Bathyraja Parmifera) для получения структурообразователя

The possibility of creating a setting agent containing collagen from the skin of a stingray (Bathyraja parmifera) is studied. The conditions of skin pretreatment (autoproteolysis), alkaline and hydrothermal treatment regimens are substantiated. Based on the study on protein content, including collagencontaining substances and viscosity, it was shown that the reasonable ratio for hydrothermal treatment is 1:1, temperature - 50 ° C, time - 2 hours.

Freeze-Drying of Blueberries: Effects of Carbon Dioxide (CO2) Laser Perforation as Skin Pretreatment to Improve Mass Transfer, Primary Drying Time, and Quality.

Freeze-dried berry fruits are generally consumed as they are, whole and without peeling or cutting, as the conservation of their original shape and appearance is often desired for the final product. However, usually, berries are naturally wrapped by an outer skin that imparts a barrier to vapor flow during freeze-drying, causing berry busting. Photo-sequence, experimental, and theoretical methodologies were applied to evaluate the application of CO2 laser microperforations to blueberry skin. Under the same set of freeze-drying conditions, blueberries with and without perforations were processed. The results showed that the primary drying time was significantly reduced from 17 ± 0.9 h for nontreated berries to 13 ± 2.0 h when nine microperforations per berry fruit were made. Concomitantly, the quality was also significantly improved, as the percentage of nonbusted blueberries at the end of the process increased from an average of 47% to 86%. From a phenomenological perspective, the analysis of the mass transfer resistance of nontreated fruits, in agreement with reported studies, showed a Type II curvature, with a sharp decrease at low time, followed by a linear increase. In contrast, blueberries with nine perforations depicted a Type III regime, with a saturation curvature toward the time axis. It was demonstrated that CO2-laser microperforation has high potential as a skin pretreatment for the freeze-drying of blueberries.

Enhanced topical cutaneous delivery of indocyanine green after various pretreatment regimens: comparison of fractional CO2 laser, fractional Er:YAG laser, microneedling, and radiofrequency

Different devices have been used to enhance topical drug delivery. Aim of this study was to compare the efficacy of different skin pretreatment regimens in topical drug delivery. In six ex vivo human abdominal skin samples, test regions were pretreated with fractional CO2 and Er:YAG laser (both 70 and 300 μm ablation depth, density of 5%), microneedling (500 μm needle length), fractional radiofrequency (ablation depth of ± 80–90 μm), and no pretreatment. The fluorescent agent indocyanine green (ICG) was applied. After 3 h, fluorescence intensity was measured at several depths using fluorescence photography. Significantly higher surface fluorescence intensities were found for pretreatment with fractional Er:YAG and CO2 laser and for microneedling vs. no pretreatment (p < 0.05), but not for radiofrequency vs. no pretreatment (p = 0.173). Fluorescence intensity was highest for the Er:YAG laser with 300 μm ablation depth (mean 38.89 arbitrary units; AU), followed by microneedling (33.02 AU) and CO2 laser with 300 μm ablation depth (26.25 AU). Pretreatment with both lasers with 300 μm ablation depth gave higher fluorescence intensity than with 70 μm ablation depth (Er:YAG laser, 21.65; CO2 laser, 18.50 AU). Mean fluorescence intensity for radiofrequency was 15.27 AU. Results were comparable at 200 and 400 μm depth in the skin. Pretreatment of the skin with fractional CO2 laser, fractional Er:YAG laser, and microneedling is effective for topical ICG delivery, while fractional radiofrequency is not. Deeper laser ablation results in improved ICG delivery. These findings may be relevant for the delivery of other drugs with comparable molecular properties.

Promotion of Wound Healing and Prevention of Frostbite Injury in Rat Skin by Exopolysaccharide from the Arctic Marine Bacterium Polaribacter sp. SM1127.

Many marine microorganisms synthesize exopolysaccharides (EPSs), and some of these EPSs have been reported to have potential in different fields. However, the pharmaceutical potentials of marine EPSs are rarely reported. The EPS secreted by the Artic marine bacterium Polaribacter sp. SM1127 has good antioxidant activity, outstanding moisture-retention ability, and considerable protective property on human dermal fibroblasts (HDFs) at low temperature. Here, the effects of SM1127 EPS on skin wound healing and frostbite injury prevention were studied. Scratch wound assay showed that SM1127 EPS could stimulate the migration of HDFs. In the full-thickness cutaneous wound experiment of Sprague–Dawley (SD) rats, SM1127 EPS increased the wound healing rate and stimulated tissue repair detected by macroscopic observation and histologic examination, showing the ability of SM1127 EPS to promote skin wound healing. In the skin frostbite experiment of SD rats, pretreatment of rat skin with SM1127 EPS increased the rate of frostbite wound healing and promoted the repair of the injured skin significantly, indicating the good effect of SM1127 EPS on frostbite injury prevention. These results suggest the promising potential of SM1127 EPS in the pharmaceutical area to promote skin wound healing and prevent frostbite injury.

Lugdunin amplifies innate immune responses in the skin in synergy with host- and microbiota-derived factors

Recently our groups discovered lugdunin, a new cyclic peptide antibiotic that inhibits Staphylococcus aureus epithelial colonization in humans and rodents. In this work, we analyzed its immuno-modulatory and antimicrobial potential as a single agent or in combination with other microbiota- or host-derived factors. We show that pretreatment of primary human keratinocytes or mouse skin with lugdunin in combination with microbiota-derived factors results in a significant reduction of S. aureus colonization. Moreover, lugdunin increases expression and release of LL-37 and CXCL8/MIP-2 in human keratinocytes and mouse skin, and results in the recruitment of monocytes and neutrophils in vivo, both by a TLR/MyD88-dependent mechanism. Interestingly, S. aureus elimination by lugdunin is additionally achieved by synergistic antimicrobial activity with LL-37 and dermcidin-derived peptides. In summary, our results indicate that lugdunin provides multi-level protection against S. aureus and may thus become a promising treatment option for S. aureus skin infections in the future.

The effect of alkaline pretreatment on the biochemical characteristics and fibril-forming abilities of types I and II collagen extracted from bester sturgeon by-products.

Non-mammalian collagens have attracted increasing attention for industrial and biomedical use. We have therefore evaluated extraction conditions and the biochemical properties of collagens from aquacultured sturgeon. Pepsin-soluble type I and type II collagen were respectively extracted from the skin and notochord of bester sturgeon by-products, with yields of 63.9 ± 0.19% and 35.5 ± 0.68%. Collagen extraction efficiency was improved by an alkaline pretreatment of the skin and notochord (fewer extraction cycles were required), but the final yields decreased to 56.2 ± 0.84% for type I and 31.8 ± 1.13% for type II. Alkaline pretreatment did not affect the thermal stability or triple-helical structure of both types of collagen. Types I and II collagen formed re-assembled fibril structures in vitro, under different conditions. Alkaline pretreatment slowed down the formation of type I collagen fibrils and specifically inhibited the formation of thick fibril-bundle structures. In contrast, alkaline pretreatment did not change type II collagen fibril formation. In conclusion, alkaline pretreatment of sturgeon skin and notochord is an effective method to accelerate collagen extraction process of types I and II collagen without changing their biochemical properties. However, it decreases the yield of both collagens and specifically changes the fibril-forming ability of type I collagen.

Insight into imiquimod skin permeation and increased delivery using microneedle pre-treatment

Basal cell carcinoma (BCC) is the most common skin cancer in humans. Topical treatment with imiquimod provides a non-invasive, self-administered treatment with relatively low treatment cost. Despite displaying excellent efficacy, imiquimod is only licensed by the FDA for superficial BCC. The current work employed HPLC and ToF-SIMS analysis to provide a novel assessment of imiquimod permeation from Aldara™ cream in skin depth and lateral distribution. Using Aldara™ cream and in vitro Franz cell studies with subsequent HPLC analysis, it is apparent that most of the topically applied imiquimod cream is left on the skin surface with more than 80% of the drug being recovered from skin wash. In addition, ToF-SIMS chemical imaging of recovered tape stripped skin samples illustrated significant detection of imiquimod signal over the entire skin area for the upper tape strips, whereas the deeper strips show large portions of the skin area without detected imiquimod. Given the limited permeation depth and non-uniform permeation observed at tape strips 6–18 when applied as a topical imiquimod cream, a permeation enhancement strategy utilising a skin pre-treatment with a microneedle device was investigated as a method to improve intradermal delivery. The recovered amount of imiquimod in tape strips and remaining skin determined by HPLC was approximately three times higher when Aldara™ was applied on microneedle pre-treated skin relative to intact skin. The ToF-SIMS ion images of the tape strips and cross-sections illustrated the existence of imiquimod in the microchannels which then laterally diffuses to peripheral epidermal strata. The current work demonstrates the first known attempt to enhance intradermal delivery of imiquimod using a microneedle device as well as underscoring the complementary role of ToF-SIMS analysis in chemically mapping imiquimod permeation into the skin with high sensitivity.

Recruitment and Collection of Dermal Interstitial Fluid Using a Microneedle Patch

Interstitial fluid (ISF) that surrounds cells in tissues of the body is a novel source of biomarker that complements conventional sources like blood, urine, and saliva. To overcome difficulties in harvesting ISF, a minimally invasive, rapid, simple-to-use, cost-effective method is developed to collect ISF from the skin involving a microneedle (MN) patch. By pressing 650 µm long MNs at an angle just below the skin surface, blood-free ISF flows through micropores to the skin surface and is absorbed into a thin strip of paper on the MN patch backing for subsequent analysis. An optimized method in rat skin in vivo is well tolerated and able to collect >2 µL of ISF within 1 min. Brief skin pretreatment with MNs followed by a 5 min delay dramatically increases subsequent ISF collection by a mechanism believed to involve increased skin hydration. ISF collection using an MN patch has the potential to simplify access to biomarkers in ISF for research and future medical diagnostic and monitoring applications.

Transdermal delivery of water-soluble fluorescent antibody mediated by fractional Er:YAG laser for the diagnosis of lupus erythematosus in mice.

Although transdermal drug delivery system (TDDS) has been successfully used for delivering small molecules, its application in the delivery of diagnostic antibodies has been limited due to their large size. In this study, we aim to obtain a broad insight in the dynamics of TRITC-conjugated Goat Anti-Mouse IgG (T-IgG) uptake in fractional Er:YAG laser pretreated skin and provide a new technical option for detecting lupus erythematosus (LE) in mice. The skins of SD and MRL/lpr mice were treated by fractional Er:YAG laser followed by external application of T-IgG. The classic Franz diffusion method was used to observe the effects of different fractional fluences, densities and antibody concentrations on transdermal delivery of T-IgG at different time points (2, 4, 6, 8, 20, and 24 hours). Frozen tissue sections and confocal microscopy were used to observe the distribution of T-IgG on the sagittal and coronal planes of murine skin. Increased laser fluence (12.5 J/cm2 to 37.5 J/cm2 ) within 24 hours resulted in the obvious increase in transdermal amounts of T-IgG during the early stage (before 8 hours). However, increasing laser density (100 pores/cm2 to 200 pores/cm2 ) produced a significant increase in T-IgG permeation during the late stage (20 and 24 hours). Unlike fluence and density, increase in T-IgG loading concentration (0.5 to 2 μg/μl) led to continuous increase in the whole process of transdermal delivery. T-IgG appeared in the micro-pores of SD mice skin within 4 hours after treatment in vivo. After 24 hours, it was observed in the skin. In MRL/lpr mice, positive lupus band testing (LBT) could be found on the skin lesion after laser and T-IgG external application. Fractional Er:YAG laser can help antibodies (150 kDa) to implement effective and controllable transdermal delivery. LBT can be achieved in MRL/lpr mice using TDDS in vivo, which may contribute to the minimally invasive diagnosis of LE. Lasers Surg. Med. 51:268-277, 2019. © 2018 Wiley Periodicals, Inc.

Effect of dosing regimen and microneedle pretreatment on in vitro skin retention of topically applied beta-blockers.

Topical beta-blocker formulations are commonly used to treat infantile hemangiomas (IHs); however, the skin concentrations and drug permeation through the skin have not been quantified. Microneedles (MNs) may increase local skin concentrations, which could further enhance lesion clearance and improve dosing regimens. The objective of this study was to quantify skin concentrations and drug permeation of two beta-blockers, propranolol and timolol, in vitro after application to intact skin and skin pretreated with solid MNs of two lengths. Propranolol skin concentrations and drug permeation were significantly higher than timolol skin concentrations for all study conditions, which is likely due to the lipophilic nature of propranolol compared to the hydrophilicity of timolol. Propranolol skin concentrations were significantly influenced by dosing regimen, as skin concentrations increased with increasing drug application. Pretreatment of the skin with solid 250μm and 500μm length MNs increased local skin concentrations of timolol; propranolol skin concentrations did not significantly increase after MN pretreatment. Propranolol and timolol permeation through the skin increased after MN pretreatment with both MN lengths for both compounds. Taken together, solid MN pretreatment prior to application of topical timolol may be beneficial for deep or mixed IHs upon further optimization of the MN treatment paradigm.

Efficacy and safety of daylight photodynamic therapy after tailored pretreatment with ablative fractional laser or microdermabrasion: a randomized, side-by-side, single-blind trial in patients with actinic keratosis and large-area field cancerization.

Physical pretreatments can potentiate the efficacy of daylight photodynamic therapy (dPDT), but clinical comparative studies remain limited. Performed in large skin areas with actinic keratoses (AKs) and photodamage, this blinded, randomized clinical trial compared the efficacy and safety of dPDT after tailored skin pretreatment using ablative fractional laser (AFL) or microdermabrasion (MD). Two ≥ 50-cm2 side-by-side skin areas were randomized to receive a single treatment with AFL-dPDT or MD-dPDT. Pretreatment parameters were tailored according to AK grade and skin constitution to ensure standardized immediate end points. Subsequently, methyl aminolaevulinate was applied, followed by 2-h daylight exposure. The primary outcome comprised blinded assessment of AK clearance at the 3-month follow-up. In 18 patients with 832 AKs, AFL-dPDT provided significantly higher AK clearance (81% vs. 60%, P < 0·001), led to fewer new AKs (P < 0·001) and showed superior improvement in dyspigmentation (P = 0·003) and skin texture (P = 0·001) vs. MD-dPDT. Peaking at days 3-6, AFL-PDT induced more intensified local skin responses (P = 0·004), including instances of Staphylococcus aureus infection (n = 3). Patients nonetheless preferred AFL-dPDT (P = 0·077), due to lower pretreatment-related pain (P = 0·002) and superior cosmesis (P = 0·035) and efficacy compared with MD-dPDT. AFL-dPDT is an effective treatment for patients with AK with extensive field cancerization, although AFL pretreatment is associated with intensified local skin reactions.

Combined use of biocompatible nanoemulsions and solid microneedles to improve transport of a model NSAID across the skin: In vitro and in vivo studies

This study aimed to investigate the potential of lecithin-based nanoemulsions costabilized by sucrose esters, with and without skin pretreatment with stainless steel microneedles, to improve delivery of aceclofenac, as a model drug, into/across the skin. The characterization revealed favorable droplet size (about 180 nm), narrow size distribution (<0.15), high surface charge (about −40 mV) and satisfying long-term stability (one year at 4 ± 1 °C) of the formulation costabilized by sucrose palmitate, demonstrating a similar trend observed for the reference stabilized by widely used lecithin/polysorbate 80 combination. In vitro release/permeation testing and differential stripping on the porcine ear proved the superiority of the sucrose ester- over polysorbate-based nanoemulsion. However, in vitro findings were not fully indicative of the in vivo performances – no significant differences were observed between investigated formulations in pharmacokinetic profile and total amount of aceclofenac deposited in the rat skin 24 h after dosing, simultaneously pointing to delayed aceclofenac delivery into the systemic circulation. In addition, the ratio of plasma concentrations of aceclofenac and its major metabolite in rats, diclofenac, was remarkably changed after topical application of tested nanoemulsions compared to intravenous administration of aceclofenac solution. Finally, skin pretreatment with microneedles improved aceclofenac delivery into/across the rat skin from tested formulations, resulting in 1.4–2.1-fold increased bioavailability and 1.2–1.7-fold enhanced level of aceclofenac retained in the skin, as measured 24 h after administration. Moreover, the plasma concentrations of aceclofenac 24 h after application of tested formulations (lecithin/sucrose palmitate vs. lecithin/polysorbate 80) combined with microneedles (173.37 ± 40.50 ng/ml vs. 259.23 ± 73.18 ng/ml) were significantly higher than those obtained through intact skin (105.69 ± 19.53 ng/ml vs. 88.38 ± 14.46 ng/ml). However, obtained results suggest that combination of microneedles and sucrose palmitate-costabilized nanoemulsion could be useful to attain higher skin concentration, while combination of microneedles with polysorbate 80-costabilized nanoemulsion could be a preferable option for enhancing drug delivery into the bloodstream.

Effects of Different Stem Skin and Marrow Root Mesh Sizes in Sweet Sorghum Bagasse on the Release of Sugar in Hydrolysis

This study investigates the effects of different particle sizes of sweet sorghum stem skin and marrow on pretreatment and hydrolysis. The optimal pretreatment concentration was 3.5% acid and 6.5% alkali. The optimal pretreatment temperature was 35 °C. Solid recovery gradually decreased with an increase in mesh and achieved 41.05% at 100 mesh under selected pretreatment conditions. The surface of the pretreated stem skin and marrow became rugged and pores were emerged. In addition, pore size was larger compared with untreated specimens. Pore diameter Dv (d) could reach 57.4 μm. For enzymatic hydrolysis, 20 units/g cellulase and 40 units/g β-glucosidase were adopted, and ten types of monosaccharide were obtained, including glucose, xylose, arabinose, galactose, mannose, ribose, fucose, gluconic acid, gluconic acid and rhamnose. The total monosaccharide content for stem skin and marrow were reached 1381.99 ± 0.7 mg/kg at 100 mesh with a two-stage (alkali–acid) pretreatment.

Syringic acid prevents skin carcinogenesis via regulation of NoX and EGFR signaling

Validation of nutraceutical and pharmaceutical targets is essential for the prediction of physiological and side effects. Epidemiologic evidence and molecular studies suggest that non-melanoma skin cancer is directly associated with excessive exposure to ultraviolet (UV) radiation. The aim of the present study was to evaluate the inhibitory effects of syringic acid on UVB-induced signaling and skin carcinogenesis, and determine the molecular targets. Treatment of human epidermal keratinocytes (HaCaT) cells with syringic acid resulted in the suppression of UVB-induced cyclooxygenase-2, matrix metalloproteinase-1, and prostaglandin E2 expression as well as activator protein-1 activity. Moreover, syringic acid inhibited the UVB-induced phosphorylation of mitogen-activated protein kinases and Akt signaling pathways as well as epidermal growth factor receptor (EGFR). Syringic acid treatment further inhibited intracellular reactive oxygen species and protein-tyrosine phosphatase-κ activity, a regulator of EGFR activation. Syringic acid and the antioxidant N-acetyl-l-cysteine inhibited UVB-induced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. In vivo, pretreatment of mouse skin with syringic acid significantly suppressed UVB-induced skin tumor incidence in a dose-dependent manner. Overall, these results indicate that syringic acid exerts potent chemopreventive activity in skin carcinogenesis mainly by inhibition of the Nox/PTP-κ/EGFR axis. Syringic acid might serve as an effective chemopreventive and therapeutic agent against UVB-mediated skin cancer.

Analysis of the effect of promoter type and skin pretreatment on antigen expression and antibody response after gene gun-based immunization.

Monoclonal antibodies (mAbs) have enabled numerous basic research discoveries and therapeutic approaches for many protein classes. However, there still exist a number of target classes, such as multi-pass membrane proteins, for which antibody discovery is difficult, due in part to lack of high quality, recombinant protein. Here we describe the impact of several parameters on antigen expression and the development of mAbs against human claudin 4 (CLDN4), a potential multi-indication cancer target. Using gene gun-based DNA delivery and bioluminescence imaging, we optimize promoter type by comparing expression profiles of four robust in vivo promoters. In addition, we observe that most vectors rapidly lose expression, ultimately reaching almost background levels by three days post-delivery. Recognizing this limitation, we next explored skin pretreatment strategies as an orthogonal method to further boost the efficiency of mAb generation. We show that SDS pretreatment can boost antigen expression, but fails to significantly increase mAb discovery efficiency. In contrast, we find that sandpaper pretreatment yields 5-fold more FACS+ anti-CLDN4 hybridomas, without impacting antigen expression. Our findings coupled with other strategies to improve DNA immunizations should improve the success of mAb discovery against other challenging targets and enable the generation of critical research tools and therapeutic candidates.

Autolysis of bovine skin, its endogenous proteases, protease inhibitors and their effects on quality characteristics of extracted gelatin

The autolysis of pretreated bovine skin (PBS) (treated with 0.1 M NaOH and 1% HCl), its endogenous proteases, inhibitors and their effects on quality attributes of gelatin were examined. PBS was subjected to different temperatures (20–90 °C) and pH (2–9) and treated with different protease inhibitors. Maximum autolytic activity of PBS was observed at 40 °C and pH 5. Ethylene-bis (oxyethylenenitrilo) tetraacetic acid (EGTA) was the most effective in impeding the degradation of γ-, β- and α- chains of PBS protein indicating that metallocollagenases were the predominant endogenous proteases in bovine skin. Gelatin was extracted in the absence (GAE) and presence (GPE) of EGTA, and EGTA with papain enzyme (GPEP). GPEP had a higher yield and lower gel strength than GEA and GPE. Metallocollagenases partook in the degradation of gelatin thereby affecting its functional properties. Pretreating PBS with or without EGTA, and papain influenced the quality attributes of gelatin.

Characterization of carp (Cyprinus carpio) skin gelatin extracted using different pretreatments method

The influence of pre-treatment method on the characteristics and gel properties of gelatine from Cyprinus carpio L. skin was studied. Gelatine was extracted from the carp skin using three methods: (I) NaCl pre-treatment, (II) NaOH and ethanol pre-treatment and (III) NaOH, H2SO4, C6H8O7 pre-treatment. The chemical composition and functional properties of gelatine were investigated. The gelatines had high protein (75.86–82.44%) and relatively high fat contents (3.99–10.02%). Electrophoresis showed that gelatines I and III contained α- and β-chains as the predominant components, while in gelatine I the distinctive bands corresponding to the main components of collagen were not observed. Amino acids analysis revealed high proline and hydroxyproline content in all the gelatines.The gel strength of gelatine III was higher than gelatines I and II. Gelatine I remained in a liquid state during the experiment. Moreover, the pre-treatment of carp skin significantly affected the colour, pH as well as foam-forming, amino-acids composition, water-binding and fat-binding properties. Gelatine III was the only gelatine with properties sufficient for industrial applications. The results indicate that C. carpio L. skin by-products can be utilised to extract gelatine with potential industrial application as an alternative source to the mammalian gelatine.

5-Fluorouracil ethosomes – skin deposition and melanoma permeation synergism with microwave

This study focuses on the use of ethosome and microwave technologies to facilitate skin penetration and/or deposition of 5-fluorouracil in vitro and in vivo. Low ethanol ethosomes were designed and processed by mechanical dispersion technique and had their size, zeta potential, morphology, drug content and encapsulation efficiency characterized. The skin was pre-treated with microwave at 2450 MHz for 2.5 min with ethosomes applied topically and subjected to in vitro and in vivo skin drug permeation as well as retention evaluation. The drug and/or ethosomes cytotoxicity, uptake and intracellular trafficking by SKMEL-28 melanoma cell culture were evaluated. Pre-treatment of skin by microwave promoted significant drug deposition in skin from ethosomes in vitro while keeping the level of drug permeation unaffected. Similar observations were obtained in vivo with reduced drug permeation into blood. Combination ethosome and microwave technologies enhanced intracellular localization of ethosomes through fluidization of cell membrane lipidic components as well as facilitating endocytosis by means of clathrin, macropinocytosis and in particularly lipid rafts pathways. The synergistic use of microwave and ethosomes opens a new horizon for skin malignant melanoma treatment.