Melatonin/Sericin Wound Healing Patches: Implications for Melanoma Therapy.

Melatonin and sericin exhibit antioxidant properties and may be useful in topical wound healing patches by maintaining redox balance, cell integrity, and regulating the inflammatory response. In human skin, melatonin suppresses damage caused by ultraviolet radiation (UVR) which involves numerous mechanisms associated with reactive oxygen species/reactive nitrogen species (ROS/RNS) generation and enhancing apoptosis. Sericin is a protein mainly composed of glycine, serine, aspartic acid, and threonine amino acids removed from the silkworm cocoon (particularly Bombyx mori and other species). It is of interest because of its biodegradability, anti-oxidative, and anti-bacterial properties. Sericin inhibits tyrosinase activity and promotes cell proliferation that can be supportive and useful in melanoma treatment. In recent years, wound healing patches containing sericin and melatonin individually have attracted significant attention by the scientific community. In this review, we summarize the state of innovation of such patches during 2021-2023. To date, melatonin/sericin-polymer patches for application in post-operational wound healing treatment has been only sparingly investigated and it is an imperative to consider these materials as a promising approach targeting for skin tissue engineering or regenerative dermatology.

Investigation of miscibiliy and physicochemical properties of synthetic polypeptide with collagen blends and their wound healing characteristics.

A suitable condition is needed to foster a rapid recovery of wounds, which is a dynamic and intricate process. The development and characterization of mats of plastic-like peptide polymer (PLP) with collagen for wound healing applications are reported in this work. Viscosity parameters such as the Huggins coefficient [KH], the intrinsic viscosity [η], α by Sun, ∆[η]m by Garcia ∆B and µ suggested by Chee, ∆K, and ß advocated by Jiang and Han, recommend the miscibility of the polypeptide in solution phase. Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD) methods in a solid phase. Thermal characteristics using a differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) showed higher stability for the blends than the pure polymers. The collagen and PLP blends showed exceptional in vitro cytocompatibility, and the in vivo wound-healing studies on the Sprague-Dawley rats demonstrated faster wound healing within two weeks compared to the cotton gauze-treated injuries. Therefore, these membranes can be a possible alternative for treating skin injuries.

Natural Plant-Derived Compounds in Food and Cosmetics: A Paradigm of Shikonin and Its Derivatives.

Shikonin and its derivatives are the natural naphthoquinone compounds produced in the roots of the Boraginaceae family. These red pigments have been used for a long time in coloring silk, as food colorants, and in the Chinese traditional system of medicines The resurgence of public interest in natural and plant-based products has led to this category of compounds being in high demand due to their wide range of biological activities including antioxidant, antitumor, antifungal, anti-inflammatory ones. Different researchers worldwide have reported various applications of shikonin derivatives in the area of pharmacology. Nevertheless, the use of these compounds in the food and cosmetics fields needs to be explored more in order to make them available for commercial utilization in various food industries as a packaging material and to enhance their shelf life without any side effects. Similarly, the antioxidant properties and skin whitening effects of these bioactive molecules may be used successfully in various cosmetic formulations. The present review delves into the updated knowledge on the various properties of shikonin derivatives in relation to food and cosmetics. The pharmacological effects of these bioactive compounds are also highlighted. Based on various studies, it can be concluded that these natural bioactive molecules have potential to be used in different sectors, including functional food, food additives, skin, health care, and to cure various diseases. Further research is required for the sustainable production of these compounds with minimum disturbances to the environment and in order to make them available in the market at an economic price. Simultaneous studies utilizing recent techniques in computational biology, bioinformatics, molecular docking, and artificial intelligence in laboratory and clinical trials would further help in making these potential candidates promising alternative natural bioactive therapeutics with multiple uses.

Scaffolds Loaded with Dialdehyde Chitosan and Collagen-Their Physico-Chemical Properties and Biological Assessment.

In this work, dialdehyde chitosan (DAC) and collagen (Coll) scaffolds have been prepared and their physico-chemical properties have been evaluated. Their structural properties were studied by Fourier Transform Infrared Spectroscopy with Attenuated Internal Reflection (FTIR-ATR) accompanied by evaluation of thermal stability, porosity, density, moisture content and microstructure by Scanning Electron Microscopy-SEM. Additionally, cutaneous assessment using human epidermal keratinocytes (NHEK), dermal fibroblasts (NHDF) and melanoma cells (A375 and G-361) was performed. Based on thermal studies, two regions in DTG curves could be distinguished in each type of scaffold, what can be assigned to the elimination of water and the polymeric structure degradation of the materials components. The type of scaffold had no major effect on the porosity of the materials, but the water content of the materials decreased with increasing dialdehyde chitosan content in subjected matrices. Briefly, a drop in proliferation was noticed for scaffolds containing 20DAC/80Coll compared to matrices with collagen alone. Furthermore, increased content of DAC (50DAC/50Coll) either significantly induced the proliferation rate or maintains its ratio compared to the control matrix. This delivery is a promising technique for additional explorations targeting therapies in regenerative dermatology. The using of dialdehyde chitosan as one of the main scaffolds components is the novelty in terms of bioengineering.

Plant-Derived Colorants for Food, Cosmetic and Textile Industries: A Review.

This review provides a report on properties and recent research advances in the application of plant-derived colorants in food, cosmetics and textile materials. The following colorants are reviewed: Polyphenols (anthocyanins, flavonol-quercetin and curcumin), isoprenoids (iridoids, carotenoids and quinones), N-heterocyclic compounds (betalains and indigoids), melanins and tetrapyrroles with potential application in industry. Future aspects regarding applications of plant-derived colorants in the coloration of various materials are also discussed.

Insights into the miscibility characteristics of plastic-mimetic polypeptide with hydroxypropylmethylcellulose: Investigation of thermal degradability and intermolecular interactions.

In this investigation, we integrated the parent recurring sequence of the plastic-derived polypeptide, poly[0.8(AVGVP),0.2(AEGVP)] (A, V, G, P, and E represents Alanine, Valine, Glycine, Proline, and Glutamic acid respectively) followed by characterization with inverse transition temperature, 13C, and 1H-NMR spectroscopy. The miscibility attributes of poly[0.8(AVGVP),0.2(AEGVP)] with Hydroxypropylmethylcellulose was examined both in aqueous and solid-phase. The Huggins' co-efficient [KH], the intrinsic viscosity [η], the interaction parameters ΔB and µ suggested by Chee, ΔK and ß recommended by Jiang and Han, α by Sun, Δ[η]m by Garcia showed that the polypeptide was miscible with HPMC in all proportions. DSC studies revealed single Tg values, and TGA manifested the enhanced thermal stability for all the proportions compared with their individuals. Further, verified the results by SEM and XRD. The FTIR evidenced existence of intermolecular hydrogen bonding between the two constituent polymers that caused the miscible blend system.

Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

The aim of this work was to compare physicochemical properties of three dimensional scaffolds based on silk fibroin, collagen and chitosan blends, cross-linked with dialdehyde starch (DAS) and dialdehyde chitosan (DAC). DAS was commercially available, while DAC was obtained by one-step synthesis. Structure and physicochemical properties of the materials were characterized using Fourier transfer infrared spectroscopy with attenuated total reflectance device (FTIR-ATR), swelling behavior and water content measurements, porosity and density observations, scanning electron microscopy imaging (SEM), mechanical properties evaluation and thermogravimetric analysis. Metabolic activity with AlamarBlue assay and live/dead fluorescence staining were performed to evaluate the cytocompatibility of the obtained materials with MG-63 osteoblast-like cells. The results showed that the properties of the scaffolds based on silk fibroin, collagen and chitosan can be modified by chemical cross-linking with DAS and DAC. It was found that DAS and DAC have different influence on the properties of biopolymeric scaffolds. Materials cross-linked with DAS were characterized by higher swelling ability (~4000% for DAS cross-linked materials; ~2500% for DAC cross-linked materials), they had lower density (Coll/CTS/30SF scaffold cross-linked with DAS: 21.8 ± 2.4 g/cm3; cross-linked with DAC: 14.6 ± 0.7 g/cm3) and lower mechanical properties (maximum deformation for DAC cross-linked scaffolds was about 69%; for DAS cross-linked scaffolds it was in the range of 12.67 ± 1.51% and 19.83 ± 1.30%) in comparison to materials cross-linked with DAC. Additionally, scaffolds cross-linked with DAS exhibited higher biocompatibility than those cross-linked with DAC. However, the obtained results showed that both types of scaffolds can provide the support required in regenerative medicine and tissue engineering. The scaffolds presented in the present work can be potentially used in bone tissue engineering to facilitate healing of small bone defects.

The impact of medicinal brines on microbial biofilm formation on inhalation equipment surfaces.

Materials such as polyvinyl chloride, polypropylene, and polyethylene are used for the construction of medical equipment, including inhalation equipment. Inhalation equipment, because of the wet conditions and good oxygenation, constitutes a perfect environment for microbial biofilm formation. Biofilms may affect microbiological cleanliness of inhalation facilities and installations and promote the development of pathogenic bacteria. Microbial biofilms can form even in saline environments. Therefore, the aim of this study was to evaluate the effect of medicinal brines on microbial biofilm formation on the surfaces of inhalation equipment. The study confirmed the high risk of biofilm formation on surfaces used in inhalation equipment. Isolated microorganisms belonged to potential pathogens of the respiratory system, which can pose a health threat to hospital patients. The introduction of additional contaminants increased the amount of bacterial biofilm. On the other hand, the presence of brines significantly limited the amount of biofilm, thus eliminating the risk of infections.

Modification by UV radiation of the surface of thin films based on collagen extracted from fish scales.

Collagen was extracted from fish scales (Esox lucius) through demineralization process. Thin films by solvent evaporation from collagen extracted from fish scales were prepared. The surface of thin films made of fish scales collagen was modified by ultraviolet (UV)-irradiation with the wavelength λ = 254 nm. The amino acid composition of the Esox lucius scale collagen was analyzed before and after UV-irradiation by means of high-pressure liquid chromatography. The surface properties of films were investigated using the technique of atomic force microscopy (AFM) and by means of contact angle measurements allowing the calculation of surface free energy. Measurements of the contact angle for diiodomethane (D) and glycerol (G) on the surface of fish collagen films were made and surface free energy was calculated. The structure of collagen before and after UV-irradiation was studied using Fourier-transform infrared spectroscopy. It was found that after UV-irradiation the amount of all amino acids present in collagen molecule decreased. It was found also that the contact angle and the surface free energy were altered by UV-irradiation of collagen film. AFM showed that the surface roughness of collagen films was also altered by UV-irradiation. UV-irradiation caused the decrease of surface roughness due to photochemical processes, which occurred in the top layer of collagen film. The formation of collagen fibrils after solvent evaporation was observed using AFM. The diameter of collagen fibrils was bigger for irradiated collagen film than the diameter of collagen fibrils before UV-irradiation.

[Comparison of growth of the follicle and mesenchymal stem cells to urothelial cells and fibroblasts on collagen scaffold]. / Porównanie wzrostu komórek macierzystych mieszków wlosowych i szpiku kostnego do wzrostu komórek urotelialnych i fibroblastów na matrycy z kolagenu typu I.

UNLABELLED: To develop a tissue-engineered bladder wall replacement with elements obtained from non-urinary tract components is an atractive idea. The aim of this study was to compare growth of hair follicles epithelial stem cells and mesenchymal stem cells to urothelial cells and fibroblasts cells on scaffold prepared from rat collagen type I. MATERIALS AND METHODS: Wistar rats were used in experiment. Rat urothelial cells, hair follicles epithelial stem cells, mesenchymal stem cells and 3T3 cells were cultivated in DMEM (Sigma) supplemented with 10% (or 20% for hair follicles cells) of Fetal Bovine Serum (FBS). Epithelial cell cultures were suplemented with EGF (10 ng/ml; Sigma). Cells were stained using anti-cytokeratine (Clone MMF) and anti-cytokeratine 7. Anti-CD34 and anti-p63 staining were done. Collagen scaffold was prepared from tendoms of Wistar rat's tails. 6-well plates were covered with collagen scaffold. 25 x 10(3) of cells were seeded on each well and cultured for a week. Cells in the controls were seeded on polystyrene surface. After a week cell viability was assessed using MTT test (Sigma). Each experiment was triplicated. Photo documentation was prepared. The differences between means were compared using t-Student test. RESULTS: There were 106.5 +/- 23.4 x 10(3) and 310.7 +/- 60.7 x 10(3) of 3T3 fibroblasts growing on polystyrene and collagen, respectively (p < 0.05). The initial cell number was 25.0 x 10(3). Urothelial cells expressed epithelial markers. There were 40.0 +/- 4.2 x 10(3) and 4.5 +/- 1.8 x 10(3) urothelial cells growing on polystyrene and collagen, respectively after 7 days of culture (p < 0.01). There were 118.5 +/- 19.7 x 10(3) and 114.1 +/- 33.2 x 0(3) of mesenchymal stem cells growing on polystyrene and collagen, respectively (NS). Hair follicles epithelial cells expressed epithelial markers and were slightly positive for CD34 and p63. There were 292.5 +/- 33.3 x 10(3) and 167.4 +/- 24.9 x 10(3) of hair follicles epithelial cells growing on polystyrene and collagen, respectively (p < 0.05). Collagen scaffold decreased proliferation of follicle epithelial and urothelial cells. CONCLUSIONS: Hair follicles epithelial stem cells and mesenchymal stem cells can be potentially used in tissue-engineering, with the guarantee of the sufficient cell number for transplantation. It seems that construction in vitro of urinary bladder walls from elements obtained from non-urinary tract tissues is feasible.

Low doses of ultraviolet radiation stimulate cell activity in collagen-based scaffolds.

Cardiovascular diseases are increasingly becoming the main cause of death all over the world, leading to an increase in the economical and social burden. Vascular tissue engineering (VTE) is paving its routes toward challenging applications, focused mainly on substitutions of small-diameter blood vessels (<6 mm). Native collagen, a natural biological material which possesses extraordinary properties in terms of biocompatibility, has been extensively investigated as a scaffold for VTE. However, collagen is mainly extracted from collagen-rich native natural tissues by different harsh chemical and physical treatments, resulting in a solution susceptible to be processed for the fabrication of supports. These treatments imply the destruction of the native organization of the collagen microstructure, thus resulting in a collagen-based support less resistant in terms of mechanical properties than the native one. Therefore, different approaches have been investigated to increase these mechanical properties. Although UV irradiation present a strong potential for efficient crosslinking collagen macromolecules, the undesirable effects of UV on cell activity still remain the main challenge to be overpassed. The aim of this study was to investigate the potential of UV radiation and glycation for the crosslinking of collagen gels, with particular concern to the cells and capacity of the cells to remodel the collagen structure.

Spectroscopic studies into the influence of UV radiation on elastin in the presence of collagen.

An investigation into the influence of UV irradiation on elastin hydrolysates in the presence of collagen was carried out using UV-Vis spectroscopy and spectrofluorometry. It was found that the absorbance of elastin hydrolysates in solution increased during irradiation more than the absorbance of the elastin/collagen blend. The fluorescence of elastin hydrolysates was observed at 305nm and at 380nm after excitation at 270nm. For the elastin/collagen mixture in solution, fluorescence spectrum shows only one maximum at 305nm. UV irradiation caused fluorescence fading at 305nm. For irradiated elastin the fluorescence at 305nm decreased faster than for the irradiated elastin/collagen mixture. The maximum of the fluorescence peak was shifted for elastin by 4nm, whereas for the elastin/collagen blends the shift was only 1-2nm. All the obtained results point out the ability of mixing elastin and collagen, and suggest that the elastin/collagen mixture in solution is less sensitive to UV irradiation than elastin hydrolysates alone.

Spectroscopic studies into the influence of UV radiation on elastin hydrolysates in water solution.

An investigation into the influence of UV irradiation on elastin hydrolysates dissolved in water was carried out using UV-Vis spectroscopy and spectrofluorometry. It was found that the absorption of elastin hydrolysates in solution increased during irradiation of the sample. For fluorescence of elastin hydrolysates we observed both, a decrease and increase of this value during irradiation of the sample. After UV irradiation of the elastin solution we observed a minor increase of overall absorption, most notably between 250 nm and 280 nm. Moreover, after UV irradiation a wide peak emerged between 290 nm and 310 nm with maximum at about 305 nm. The new peak suggests that new photoproducts are formed during UV irradiation of elastin hydrolysates. The fluorescence of elastin hydrolysates was observed at 305 nm and at 380 nm after excitation at 270 nm. UV irradiation caused fluorescence fading at 305 nm and 380 nm. After 30 min of irradiation a new broad weak band of fluorescence, attributable to new photoproducts, emerged in the UV wavelength region with emission maximum between 400 nm and 500 nm.

Effects of solar radiation on collagen and chitosan films.

Photo-aging and photo-degradation are the deleterious effect of chronic exposure to sun light of many materials made of natural polymers. The resistance of the products on the action of solar radiation is very important for material scientists. The effect of solar radiation on two natural polymers: collagen and chitosan as well as collagen/chitosan blends in the form of thin films has been studied by UV-Vis and FTIR spectroscopy. It was found that UV-Vis spectra, which characterise collagen and collagen/chitosan films, were significantly altered by solar radiation. FTIR spectra of collagen and collagen/chitosan films showed that after solar irradiation the positions of amide A and amide I bands were shifted to lower wavenumbers. There was not any significant alteration of chitosan UV-Vis and FTIR spectra after solar radiation. In the condition of the experiment chitosan films were resistant to the action of solar radiation. The effect of solar UV radiation in comparison to artificial UV radiation has been discussed.

Thermal stability of UV-irradiated collagen in bovine lens capsules and in bovine cornea.

The thermal stability of UVB irradiated collagen in bovine lens capsules and in bovine cornea has been investigated by differential scanning calorimetry (DSC). During UVB irradiation the lens capsules and cornea were immersed in water to keep the collagen in a fully hydrated condition at all times. UV irradiation induced changes in collagen which caused both stabilization and destabilization of the collagen structure. The helix-coil transition for non-irradiated collagen in cornea occurred near 66 degrees C, instead for the irradiated one for 3h it occurred at 69 degrees C. After irradiating for longer times (20-96h) the helix-coil transition peak occurred at much lower temperatures. The peak was very broad and suggested that collagen was reduced by UV to different polypeptides of different molecular weight and different lower thermal stabilities. The irradiation of lens capsules with UVB light in vitro resulted in changes in the thermal properties of type-IV collagen consistent with increased cross-linking. DSC of lens capsules showed two major peaks at melting temperatures at 54 degrees C Tm1 and 78 degrees C Tm2, which can be attributed to the denaturation of the triple helix and 7S domains, respectively. UVB irradiation of lens capsules in vitro for 6 h caused an increase in Tm1 from 54 to 57 degrees C. The higher temperature required to denature the type-IV collagen after irradiation in vitro suggested an increase of intermolecular cross-linking.

Thermal denaturation of UV-irradiated wet rat tail tendon collagen.

The thermal helix-coil transition of UV irradiated collagen in rat tail tendon has been investigated by differential scanning calorimetry. During UVB irradiation the tendons were immersed in water to keep the collagen fibers in a fully hydrated condition at all times. UV irradiation induced changes in collagen which caused both stabilization and destabilization of the triple helix in fibers. The helix-coil transition for non-irradiated collagen occurred near 64 degrees C, for irradiated 1 and 3 h at 66 and 67 degrees C, respectively. After irradiating for longer times (20-66 h) the helix-coil transition peak occurred at much lower temperatures. The peak was very broad and suggested that collagen was reduced by UV to different polypeptides of different molecular weight and different lower thermal stabilities. It was caused by the disruption of a network of hydrogen-bonded water molecules surrounding the collagen macromolecule.