The role of topically applied l-ascorbic acid in ex-vivo examination of burn-injured human skin

Open-label, single-arm, single-center clinical study on the effectiveness and safety of a moisturizer containing tocotrienol-rich composition in children with mild to moderate atopic dermatitis

BACKGROUND

Little is known about antioxidant efficacy of topical vitamin E on atopic dermatitis (AD) due to lack of controlled clinical studies.

AIM

The study evaluates the effectiveness and safety of a topical moisturizer containing tocotrienol-rich composition over 12 weeks on patients aged between 1 month and 12 years with mild to moderate AD.

METHODS

We conducted a 12 weeks, prospective, open-label clinical study on the effect of tocotrienol as an adjunct to conventional treatment. This study was approved by the Ethics Committee for Research Involving Human Subject. JKEUPM-2019-274 (NMMR-19-1588-49234).

RESULTS

Thirty AD patients with a mean age of 2.77 ± 3.05 were enrolled in the study. At week-12, significant reduction of investigator global assessment (63.4%), Patient-Oriented Scoring Atopic Dermatitis Index (PO-SCORAD) (65%), and SCORAD (52.3%) was noted (p < 0.05). There was also a significant decreased in pruritus intensity (46%, p < 0.05). Similarly at week-12, Infant's Dermatitis Quality of Life Index and Children's Dermatology Life Quality Index were found to improve significantly compared to baseline (p < 0.05). Instrumental assessment revealed improvement in TEWL and erythema index, 49.7% and 17.4%, respectively. No adverse reaction was observed. 95% of patients were satisfied with the moisturizer and 90% perceived it to be better than the one in the market. There was a 55.07% reduction in the use of hydrocortisone 1% cream toward the end of the study (p < 0.05).

CONCLUSIONS

The results suggested that tocotrienol-rich moisturizer is safe and effective in the management of AD in young children.

Plant-Based, Hydrogel-like Microfibers as an Antioxidant Platform for Skin Burn Healing

Natural polymers from organic wastes have gained increasing attention in the biomedical field as resourceful second raw materials for the design of biomedical devices which can perform a specific bioactive function and eventually degrade without liberating toxic residues in the surroundings. In this context, patches and bandages, that need to support the skin wound healing process for a short amount of time to be then discarded, certainly constitute good candidates in our quest for a more environmentally friendly management. Here, we propose a plant-based microfibrous scaffold, loaded with vitamin C (VitC), a bioactive molecule which acts as a protecting agent against UV damages and as a wound healing promoter. Fibers were fabricated via electrospinning from various zein/pectin formulations, and subsequently cross-linked in the presence of Ca2+ to confer them a hydrogel-like behavior, which we exploited to tune both the drug release profile and the scaffold degradation. A comprehensive characterization of the physico-chemical properties of the zein/pectin/VitC scaffolds, either pristine or cross-linked, has been carried out, together with the bioactivity assessment with two representative skin cell populations (human dermal fibroblast cells and skin keratinocytes, HaCaT cells). Interestingly, col-1a gene expression of dermal fibroblasts increased after 3 days of growth in the presence of the microfiber extraction media, indicating that the released VitC was able to stimulate collagen mRNA production overtime. Antioxidant activity was analyzed on HaCaT cells via DCFH-DA assay, highlighting a fluorescence intensity decrease proportional to the amount of loaded VitC (down to 50 and 30%), confirming the protective effect of the matrices against oxidative stress. Finally, the most performing samples were selected for the in vivo test on a skin UVB-burn mouse model, where our constructs demonstrated to significantly reduce the inflammatory cytokines expression in the injured area (50% lower than the control), thus constituting a promising, environmentally sustainable alternative to skin patches.

Design of Novel Tricaprylin-Incorporated Multi-Layered Liposomal System for Skin Delivery of Ascorbic Acid with Improved Chemical Stability

L-ascorbic acid (Vit C) possesses a variety of dermatological functions in maintaining skin health and anti-aging properties. However, its topical application is challenging owing to its liability to light, oxygen, or heat. Therefore, in this study, a novel liposomal system, including a lipophilic neutral oil named a lipo-oil-some (LOS), was designed to improve the chemical stability and aid the skin absorption of Vit C. The vesicular systems were prepared using the ethanol injection method, employing phosphatidylcholine, cholesterol, dipalmitoyl-sn-glycerol-3-phosphoglycerol, and tricaprylin as neutral oil. The optimized LOS was characterized as follows: shape, multi-layered sphere; size, 981 nm; zeta potential, -58 mV; and Vit C encapsulation efficiency, 35%. The encapsulation of the labile compound into the novel system markedly enhanced photostability, providing over 10% higher Vit C remaining compared to Vit C solution or Vit C-loaded conventional liposome under a light intensity of 20,000 lx. On the other hand, the ex vivo skin permeation and accumulation of Vit C with the LOS system were comparable to those of smaller conventional liposomes (198 nm) in a Franz diffusion cell model mounted with porcine skin. Based on these findings, we concluded that the novel liposomal system could be utilized for skin delivery of Vit C with enhanced chemical stability.

Melanin Treatment Effect of Vacuoles-Zinc Oxide Nanoparticles Combined with Ascorbic Acid

Currently, ascorbic acid (AA) is widely used as a skin whitening material, but, AA, an unstable hydrophilic molecule, cannot penetrate the skin easily, due to the hydrophobic character of the stratum corneum. Therefore, we conjugated AA with hydrated zinc oxide-an inorganic matrix with positive surface charge, to improve the stability of AA. The metal-conjugated-ascorbic acid (ZnAA) was then combined with yeast vacuole through the vacuolar membrane proteins that relate to metal transportation to create an enhanced vacuole that contained ZnAA. The characteristics of vacuole with ZnAA (ZnAA_Vac) were next examined by various tests that included X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray (EDX) analysis. Furthermore, the ability of ZnAA_Vac to degrade melanin was confirmed in both melanoma cell line B16F10, and the artificial human skin MelanoDerm. The results showed that ZnAA_Vac possessed a higher depigmenting effect than the wild-type vacuole or ascorbic acid by reducing 75% of melanin color. Interestingly, ZnAA_Vac was found to be harmless, and did not cause any cytotoxicity to the cells. Overall, ZnAA_Vac is expected to provide a robust, harmless, and effective whitening agent for the skin.

An Evaluation of the Effect of Activation Methods on the Release of Growth Factors from Platelet-Rich Plasma

BACKGROUND

Activation of platelets in platelet-rich plasma may improve growth factor release, thus enhancing regenerative properties. The authors investigated whether different methods of platelet-rich plasma activation affected growth factor release kinetics over time.

METHODS

Platelet-rich plasma from 20 healthy volunteers was processed by six different methods: (1) control (nonactivated); (2) activation with calcium chloride; (3) activation with calcium chloride and ethanol; (4) activation with calcium chloride and ethanol at 4°C; (5) activation with calcium chloride and ethanol with vitamin C; (6) activation with calcium chloride and ethanol with vitamin C at 4°C. Concentration of secreted vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and insulin-like growth factor over 24 hours was measured by immunoassay.

RESULTS

Calcium chloride-activated platelet-rich plasma produced significantly more insulin-like growth factor at 1 hour compared to cold and vitamin C platelet-rich plasma, and calcium chloride plus ethanol produced significantly more at 24 hours compared to vitamin C platelet-rich plasma. The addition of vitamin C reduced release of PDGF over time. Activation with calcium chloride and ethanol with or without cold temperature produced a gradual PDGF release as opposed to calcium chloride alone, which caused higher PDGF within 4 hours. There were no significant differences between groups for VEGF, although calcium chloride and cooled platelet-rich plasma approached significance for producing more than vitamin C platelet-rich plasma.

CONCLUSIONS

Activation of platelet-rich plasma does not significantly improve growth factor secretion, which is made worse by the addition of vitamin C, a platelet inhibitor. Ethanol does not negatively impact growth factor production and may offer a more gradual release.

CLINICAL RELEVANCE STATEMENT

These findings will help guide platelet-rich plasma preparation methods where therapeutic growth factors are used.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Graphene Oxide as a Collagen Modifier of Amniotic Membrane and Burnt Skin

Introduction

The aim of this interdisciplinary study was to answer the question of whether active antioxidants as graphene oxide (GO), sodium ascorbate, and L-ascorbic acid modify at a molecular and supramolecular level the tissue of pathological amnion and the necrotic eschar degraded in thermal burn. We propose new solutions of modifiers based on GO that will become innovative ingredients to be used in transplants (amnion) and enhance regeneration of epidermis degraded in thermal burn.

Methods

A Nicolet 6700 spectrophotometer with Omnic software and the EasiDiff diffusion accessory were used in FTIR spectroscopic analysis. A Nicolet Magna-IR 860 spectrometer with an FT Raman accessory was used to record the Raman spectra of the samples. The surface of the samples was examined using a Phenom ProX scanning electron microscope with an energy-dispersive X-ray spectroscopy detector to diagnose and illustrate morphological effects on skin and amnion samples. SAXS measurements were carried out with a compact Kratky camera equipped with the SWAXS optical system.

Results

Characterisation of amide I-III regions, important for molecular structure, on both FTIR and FTR spectra revealed distinct shifts, testifying to organization of protein structure after GO modification. A wide lipid band associated with ester-group vibrations in phospholipids of cell membranes and vibrations of the carbonyl group of GO in the 1,790-1,720 cm^-1 band were observed in the spectra of thermally degraded and GO-modified epidermis and pathological amnion. SAXS studies revealed that GO caused a significant change in the structure of the burnt skin, but its influence on the structure of the amnion was weak.

Conclusion

Modification of burn-damaged epidermis and pathological amnion by means of GO results in stabilization and regeneration of tissue at the level of molecular (FTIR, FTR) and supramolecular (SAXS) interactions.

l-cysteine-modified chiral gold nanoparticles promote periodontal tissue regeneration

Gold nanoparticles (AuNPs) with surface-anchored molecules present tremendous potential in tissue regeneration. However, little is known about chiral-modified AuNPs. In this study, we successfully prepared L/D-cysteine-anchored AuNPs (L/D-Cys-AuNPs) and studied the effects of chiral-modified AuNPs on osteogenic differentiation and autophagy of human periodontal ligament cells (hPDLCs) and periodontal tissue regeneration. In vitro, more L-Cys-AuNPs than D-Cys-AuNPs tend to internalize in hPDLCs. L-Cys-AuNPs also significantly increased the expression of alkaline phosphatase, collagen type 1, osteocalcin, runt-related transcription factor 2, and microtubule-associated protein light chain 3 II and decreased the expression of sequestosome 1 in hPDLCs compared to the expression levels in the hPDLCs treated by D-Cys-AuNPs. In vivo tests in a rat periodontal-defect model showed that L-Cys-AuNPs had the greatest effect on periodontal-tissue regeneration. The activation of autophagy in L-Cys-AuNP-treated hPDLCs may be responsible for the cell differentiation and tissue regeneration. Therefore, compared to D-Cys-AuNPs, L-Cys-AuNPs show a better performance in cellular internalization, regulation of autophagy, cell osteogenic differentiation, and periodontal tissue regeneration. This demonstrates the immense potential of L-Cys-AuNPs for periodontal regeneration and provides a new insight into chirally modified bioactive nanomaterials.

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L/D-Cys-AuNPs exert a chirality-dependent effect on hPDLCs.

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L-Cys-AuNPs efficiently induced osteogenic differentiation in hPDLCs.

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L-Cys-AuNPs significantly improved periodontal tissue regeneration.

The Effects of Two Different Burn Dressings on Serum Oxidative Stress Indicators in Children with Partial Burn

In this study, we evaluated and compared the effect of treatment with a hydrofiber dressing with silver (HFAg) and a polylactic membrane (PLM) on systemic oxidative stress in systemic inflammatory reaction in thermal burn injuries in children. A prospective randomized and matched pairing study of 20 to 50% of TBSA was performed from children equal to both sexes affected by thermal injuries. The control group was included in normal children of both sexes. Serum malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant capacity (TOC), and glutathione (GSH) levels were analyzed and the results were analyzed statistically. In this study, it was found that PLM treatment increased TAC and GSH levels in burn patients significantly more than the other group. With the use of PLM, TOC decreased to normal level from day 3. In the HFAg group, TAC and GSH levels began to increase on the seventh day. On the first day of the burn, the TOC level started to increase. This increase continued on days 7 and 14. The TOC level began to fall on the 21st day. The increase in TAC was higher in the PLM group. In the PLM group, TOC fell faster. As a result, we think that different burn dressings can have different systemic effects. We can speculate that PLM has an antioxidant effect in the burn tissue due to high lactate content. Therefore, PLM may have decreased serum oxidative stress indicators more effectively than HFAg.

Raman spectroscopy accurately classifies burn severity in an ex vivo model

Accurate classification of burn severities is of vital importance for proper burn treatments. A recent article reported that using the combination of Raman spectroscopy and optical coherence tomography (OCT) classifies different degrees of burns with an overall accuracy of 85% [1]. In this study, we demonstrate the feasibility of using Raman spectroscopy alone to classify burn severities on ex vivo porcine skin tissues. To create different levels of burns, four burn conditions were designed: (i) 200°F for 10s, (ii) 200°F for 30s, (iii) 450°F for 10s and (iv) 450°F for 30s. Raman spectra from 500-2000cm^-1 were collected from samples of the four burn conditions as well as the unburnt condition. Classifications were performed using kernel support vector machine (KSVM) with features extracted from the spectra by principal component analysis (PCA), and partial least-square (PLS). Both techniques yielded an average accuracy of approximately 92%, which was independently evaluated by leave-one-out cross-validation (LOOCV). By comparison, PCA+KSVM provides higher accuracy in classifying severe burns, while PLS performs better in classifying mild burns. Variable importance in the projection (VIP) scores from the PLS models reveal that proteins and lipids, amide III, and amino acids are important indicators in separating unburnt or mild burns (200°F), while amide I has a more pronounced impact in separating severe burns (450°F).

Burn-related Collagen Conformational Changes in ex vivo Porcine Skin using Raman Spectroscopy

This study utilizes Raman spectroscopy to analyze the burn-induced collagen conformational changes in ex vivo porcine skin tissue. Raman spectra of wavenumbers 500-2000 cm^-1 were measured for unburnt skin as well as four different burn conditions: (i) 200 °F for 10 s, (ii) 200 °F for the 30 s, (iii) 450 °F for 10 s and (iv) 450 °F for 30 s. The overall spectra reveal that protein and amino acids-related bands have manifested structural changes including the destruction of protein-related functional groups, and transformation from α-helical to disordered structures which are correlated with increasing burn severity. The deconvolution of the amide I region (1580-1720 cm^-1) and the analysis of the sub-bands reveal a change of the secondary structure of the collagen from the α-like helix dominated to the β-aggregate dominated one. Such conformational changes may explain the softening of mechanical response in burnt tissues reported in the literature.

Ascorbic Acid in Skin Health

Ascorbic acid (vitamin C) is a water-soluble vitamin and a recognized antioxidant drug that is used topically in dermatology to treat and prevent the changes associated with photoaging, as well as for the treatment of hyperpigmentation. Ascorbic acid has neutralizing properties of free radicals, being able to interact with superoxide, hydroxyl and free oxygen ions, preventing the inflammatory processes, carcinogens, and other processes that accelerate photoaging in the skin. Current research focuses on the search for stable compounds of ascorbic acid and new alternatives for administration in the dermis. Unlike plants and most animals, humans do not have the ability to synthesize our own ascorbic acid due to the deficiency of the enzyme L-gulono-gamma-lactone oxidase, which catalyzes the passage terminal in the ascorbic acid biosynthesis. To deal with this situation, humans obtain this vitamin from the diet and/or vitamin supplements, thus preventing the development of diseases and achieving general well-being. Ascorbic acid is involved in important metabolic functions and is vital for the growth and maintenance of healthy bones, teeth, gums, ligaments, and blood vessels. Ascorbic acid is a very unstable vitamin and is easily oxidized in aqueous solutions and cosmetic formulations. Ascorbic acid is extensively used as an ingredient in anti-aging cosmetic products, as sodium ascorbate or ascorbyl palmitate. This review discusses and describes the potential roles for ascorbic acid in skin health and their clinical applications (antioxidative, photoprotective, anti-aging, and anti-pigmentary effects) of topical ascorbic acid on the skin and main mechanisms of action. Considering the instability and difficulty in administering ascorbic acid, we also discuss the importance of several factors involved in the formulation and stabilization of their topical preparations in this review.

3-O-ethyl-l-ascorbic acid: Characterisation and investigation of single solvent systems for delivery to the skin

l-ascorbic acid (AA), commonly known as vitamin C, has been widely used in topical formulations for many years as an antioxidant and anti-aging ingredient. However, the physicochemical properties of AA are not optimal for skin uptake and the molecule is also unstable, readily undergoing oxidation on exposure to air. The compound 3-o-ethyl-l-ascorbic acid (EA) has been developed as a stable vitamin C derivative and has been used in topical products. The aims of this work were to conduct a comprehensive characterisation of physicochemical properties of EA as well as to investigate the influence of various neat solvents on EA skin delivery. Nuclear magnetic resonance (NMR), mass spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterise the molecule. The pK_a of the compound and the partition coefficient logP_(o/w) were experimentally determined. A new HPLC method for analysis of the molecule was also developed and validated. A number of solvents for topical preparations were selected based on their wide use as excipients in topical formulations, their potential to act as skin penetration enhancers and their favourable safety profiles. The solubility and stability of EA was examined. Skin permeation of the molecule in full thickness porcine skin in vitro was investigated using Franz-type diffusion cells. The melting point, log P_(o/w) value and pK_a value of EA were determined to be 114.39 ± 0.5 °C, −1.07 ± 0.03 and 7.72 ± 0.01 respectively. Skin penetration of EA was evident for the following vehicles 1,2 hexanediol (HEX), glycerol (GLY), propylene glycol (PG), 1,2 pentanediol (1-2P), isopropyl alcohol (IPA), propylene glycol monolaurate (PGML) and propylene glycol monocaprylate (PGMC). Skin uptake but no permeation through the skin was observed for Transcutol® (TC) and dipropylene glycol (DiPG), while no penetration was observed for the solvents 1,5 pentanediol (1-5P) and tripropylene glycol (TriPG). The findings of the permeation experiments confirm the potential of simple formulations to deliver EA to the skin. Studies are ongoing to identify complex vehicles for synergistic enhancement of EA skin penetration. To our knowledge this is the first study to conduct a comprehensive characterization of EA and examine its skin uptake and permeation properties in porcine skin.

A Histologic Perspective on Electrical and Thermal Burn-Injured Human Skin

OBJECTIVE

To analyze specific spectroscopic (FT-Raman) and thermal (limiting oxygen index) aspects of skin samples exposed to electrical injury compared with thermal injury.

METHODS

An observational case-control study was conducted at the Dr Stanislaw Sakiel Center for Burns Treatment in Siemianowice, Silesia, Poland. A scanning electron microscope was used to diagnose and illustrate the topography of skin samples from electrical and thermal burns and the morphologic effects on damaged versus undamaged skin surfaces. In particular, researchers attempted to detect spectroscopic and thermal changes at the molecular level, namely, specific biomarkers of tissue degeneration and their regeneration under the influence of the applied modifiers (antioxidants and orthosilicic acid solutions).

RESULTS

Modification with L-ascorbic acid and hydrogel of orthosilicic acid caused an increase in the intensity of the amide I Raman peaks, whereas modification with sodium ascorbate and orthosilicic acid resulted in the separation of the band protein side chains (1,440-1,448 cm), which is a part of tissue regeneration. The best result was obtained when the skin was treated with 7% orthosilicic acid (limiting oxygen index, 26%).

CONCLUSIONS

Antioxidant treatment may be advantageous in minimizing injury in patients with thermal burns but not always in electrical burns.

FT Raman spectroscopy in the evaluation of biomarkers of normal and pathological placenta tissue

The basic precondition of proper intrauterine growth is appropriate supply of nutrients transported through placenta. Placenta capacity in the scope of transportation is dependent on transport systems and the structure of the basement membrane and syncytiotrophoblast microvillous membrane. The present pilot study demonstrates preliminary results of the analysis of placenta structure in the course of selected pathologies by FT Raman spectroscopy analysis. The observed changes of the molecular structure in the so-called average spectra, independent of methodical processing, may be an indicator of the efficiency of transportation controlled by syncytiotrophoblast. In particular, an increase in the intensity of dispersion and transfer within the frequency of 3425-3300 cm^-1 demonstrate the dynamics of the interaction in the scope of hydrogen bonds in healthy tissues. Changes in the molecular structure within the frequency of 950-750 cm^-1 and conformational changes within disulphide bonds differentiate the healthy tissue from the pathological one. Changes in the molecular structure observed in the FTR spectra are a spectroscopic image of placenta functions in the course of various pathologies. They also document a complex goal of our research that is finding spectroscopic biomarkers of regular and pathological placental tissue.

Sodium ascorbate (SA) and l-ascorbic acid (AA) as modifiers of burn affected skin - A comparative analysis

Proper functioning of living organisms requires controlling the factors which govern the level of oxidative stress in the system, that is presence of free radicals at a given, rather low, level and preventing their excess. In this work it is shown that SA and AA active antioxidants, governing the oxidative stress in the wound, modify standard serum solution as well as burn affected necrotic eschar at the molecular structure level. In the case of incubation of skin fragments in SA and AA, the following findings were reported: modification of serum, that is appearance of low molecular weight oligomer bands in AA and recreation of native serum bands in SA. In frozen serum solutions modified by AA FTIR 1759 and 1420-1053 cm^-1 bands are observed, whereas in SA FTIR 1603, 1411-1054 and 536 cm^-1 bands appear. In the case of modification of the burn affected necrotic eschar in SA and AA - frequency shifts in the fingerprint region 1780-1000 cm^-1 can be biomarkers indicating tissue regeneration process under the influence of antioxidants. 1780-1580 cm^-1 and 1418-1250 cm^-1 regions on the Raman spectra are particularly rich in spectral information. Modification of samples of skin burnt with AA activates the regions of the β-sheet aggregates whereas treatment of the samples with SA ascorbate demonstrates changes which testify to reconstruction of α-helix structure (SAXS studies).

The role of dimethyl sulfoxide (DMSO) in ex-vivo examination of human skin burn injury treatment

Dimethyl sulfoxide (DMSO) is one of the most versatile solvents in biological science, therefore it is frequently used as a solvent in biological studies and as a vehicle for drug therapy. DMSO readily penetrates, diffuses through biological membranes and ipso facto increases fluidity of liposomal membranes modelling stratum corneum. Thermal injury is associated with the appearance of lipid peroxidation products in the burned skin. The influence of DMSO on protein structure and stability is concentration and temperature dependant. The aim of this study was to assess the impact of DMSO on human burn wounds and examine the interactions between DMSO and skin surface. The real problem in burn treatment is hypoalbuminemia. At the level of the laboratory studies there was an attempt at answering the question of whether the DMSO will modify the standard serum solution. In the case of the incubation of skin fragments in 1%-100% DMSO, the following findings were reported: modification of the serum, appearance of low molecular weight oligomer bands, disappearance of albumin bands or reconstruction of native serum bands during incubation in antioxidant solutions. The result of the modification is also the exposure of FTIR 1603 and 1046cm^-1 bands observed in frozen serum solutions. In the case of modification of the burned skin by DMSO solutions or antioxidants - frequency shifts, an increase in the intensity of amide I band as well as the appearance of the 1601cm^-1 band can be specific biomarkers of the tissue regeneration process. In this study the areas 1780-1580cm^-1 and 1418-1250cm^-1 on the Raman spectra are particularly rich in spectral information.