A randomized intraindividual comparative study evaluating the effects of two ultrasound-assisted liposuction devices on the abdomen.

BACKGROUND: Ultrasound-assisted liposuction (UAL) has become popular because of its favorable outcomes in fat emulsification, blood loss reduction, and skin tightening. This study aimed to compare the effects of two UAL devices on the abdomen by assessing postsurgery skin biomechanical properties. METHODS: This single-blind, prospective study (2020-2022) involved 13 liposuction procedures performed on patients without chronic diseases. Each patient's abdomen was divided vertically from the xiphoid to the perineum. Vibration amplification of sound energy at resonance (VASER)-assisted liposuction (Solta Medical, Inc., Hayward, CA) was performed on one half, while the other half underwent liposuction with high-frequency ultrasound energy (HEUS)-assisted technology. Skin biomechanical measurements, including distensibility, net elasticity, biological elasticity, hydration, erythema, melanin, and skin firmness, were taken at 12 and 24 months postsurgery, focusing on the anterior abdomen, 8 cm to the right and left of the umbilicus. RESULTS: Analysis of the above skin biomechanical measurements revealed no significant differences between the HEUS and VASER devices, except for skin firmness, which showed a notable increase following HEUS surgery. Patient-perceived clinical differences were assessed via nonvalidated questionnaires, revealing no distinctions between devices. CONCLUSION: Biomechanical skin results post-UAL surgery with these devices on the abdomen were not significantly different, although HEUS revealed increased skin firmness. This suggests that HEUS-assisted technology, akin to other devices, is a viable option for UAL procedures.

Antiproliferative and Antimigratory Activity of Poly-gallic Acid in Cancer Cell Lines.

BACKGROUND/AIM: Enzyme-mediated grafting of poly (gallic acid) (PGAL) and L-arginine and a-L-lysine onto PGAL produces reactive oxygen species (ROS)-suppressor multiradical molecules with low cytotoxicity, high thermostability and water solubility with cancer treatment potential. This study examined the anticancer effects of these molecules in hepatic (HepG2, ATCC HB-8065), breast (MCF7, ATCC HTB-22), and prostate (PC-3, ATCC CRL-1435 and DU 145, ATCC HTB-81) cancer cell lines, as well as in fibroblasts from healthy human skin as control cells. MATERIALS AND METHODS: PGAL was synthesized by the oxidative polymerization of the naturally abundant GA using laccase from Trametes versicolor. Insertions of amino acids L-arginine and α-L-lysine on the PGAL chain were carried out by microwave. The cells of dermal fibroblast (Fb) were obtained from primary skin cultures and isolated from skin biopsies. The cancer cells lines of hepatic (HepG2), breast (MCF7), and prostate (PC-3, DU 145) were obtained from ATCC. The viability of the cancer cells and the primary culture was obtained by the MTT assay. Proliferation was demonstrated by crystal violet assay. Cell migration was determined by Wound healing assay. Finally, cell cycle analysis was carried out with cells. RESULTS: The results show that 200 µg/ml of PGAL cultured in vitro with prostate cancer cells decreased viability, proliferation, and migration, as well as arrested cells in the G1 and S phases of the cell cycle. In contrast, the dermal fibroblasts and the hepatic line remained unaffected. The random grafting of L-Arg and a-L-Lys onto the PGAL chain also decreased the viability of prostate cancer cells. CONCLUSION: PGAL and PGAL-grafted amino acids are potential adjuvants for prostate cancer treatment, with improved physicochemical characteristics compared to GA.

Effect of smoking on the redox status of knee osteoarthritis: A preliminary study.

Even though smoking has been scarcely studied in osteoarthritis (OA) etiology, it is considered a controversial risk factor for the disease. Exposure to tobacco smoke has been reported to promote oxidative stress (OS) as part of the damage mechanism. The aim of this study was to assess whether smoking increases cartilage damage through the generation of OS. Peripheral blood (PB) and synovial fluid (SF) samples from patients with OA were analyzed. The samples were stratified according to smoking habit, Kellgren-Lawrence score, pain, and cotinine concentrations in PB. Malondialdehyde (MDA), methylglyoxal (MGO), advanced protein oxidation products (APOPs), and myeloperoxidase (MPO) were assessed; the activity of antioxidant enzymes such as gamma-glutamyl transferase (GGT), glutathione S-transferase (GST) and catalase (CAT), as well as the activity of arginase, which favors the destruction of cartilage, was determined. When stratified by age, for individuals <60 years, the levels of MDA and APOPs and the activity of MPO and GST were higher, as well as antioxidant system activity in the smoking group (OA-S). A greater degree of pain in the OA-S group increased the concentrations of APOPs and arginase activity (P < 0.01 and P < 0.05, respectively). Arginase activity increased significantly with a higher degree of pain (P < 0.01). Active smoking can be an important risk factor for the development of OA by inducing systemic OS in young adults, in addition to reducing antioxidant enzymes in older adults and enhancing the degree of pain and loss of cartilage.

Antiphagocytic Properties of Polygallic Acid with Implications in Gouty Inflammation.

Polygallic acid (PGAL) has been used in vitro to protect synoviocytes from monosodium urate (MSU) crystals due to its anti-inflammatory properties. However, MSU crystals can also activate other cells of the synovial fluid (SF). We studied the impact of PGAL on the phagocytosis of MSU crystals, inflammation, and oxidative stress using an in vitro model with SF leukocytes and THP-1 monocyte cells. SF leukocytes were stimulated with PGAL and MSU crystals, proinflammatory cytokines and phagocytosis were assessed. In THP-1 cells, the effect of PGAL on the phagocytosis of MSU crystals and the levels of IL-1ß, IL-6, TNF-α, and reactive oxygen species (ROS) was evaluated. PGAL was added to THP-1 cultures 24 h before MSU crystal addition as a pre-treatment, and IL-1ß was measured. One-way ANOVA with Tukey's post hoc test was performed, and a P value < 0.05 was considered statistically significant. PGAL (100 µg/mL) decreased phagocytosis in SF leukocytes by 14% compared to cells exposed to crystals without PGAL. In THP-1 cells, 100 and 200 µg/mL PGAL reduced phagocytosis by 17% and 15%, respectively. In SF cells, there was a tendency to decrease IL-1ß and IL-6. In THP-1 cells, decreases in IL-1ß and TNF-α, as well as a slight decrease in ROS, were identified. PGAL pre-treatment resulted in a reduction of IL-1ß. PGAL inhibits MSU phagocytosis by exerting an anti-inflammatory effect on cells exposed to crystals. The use of PGAL before an acute attack of gout suggests an important protective factor to control the inflammation.

Anti-Inflammatory and Histological Analysis of Skin Wound Healing through Topical Application of Mexican Propolis.

Skin wound healing is a complex biochemical process of tissue repair and remodeling in response to injury. Currently, the drugs used to improve the healing process are inaccessible to the population, are costly, and have side effects, making the search for new treatment alternatives necessary. Propolis is a natural product produced by bees that is widely recognized and used in folk medicine for its multiple biomedical activities. However, therapeutic information regarding Mexican propolis is limited. This study aimed to evaluate the wound-healing effect of the Chihuahua ethanolic extract of propolis (ChEEP). Macroscopic and histological analyses were performed using a mouse wound-healing model. The topic acute toxicity assay showed that propolis at 10% w/v had no toxic effects. ChEEP has antibacterial activity against the Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis. Moreover, it exhibited good anti-inflammatory activity evaluated through mouse ear edema induced by 12-O-tetradeca-noylphorbol-13-acetate (TPA). A full-thickness incision lesion was created in mice and treated topically with 10% ChEEP. At Day 14 post-treatment, it was observed that propolis increased wound contraction and reduced healing time and wound length; furthermore, propolis increased the tensile strength of the wound, as determined with the tensiometric method, and promoted the formation of type I collagen at the site of injury, as evaluated with Herovici stain. These findings suggest that the topical administration of ChEEP can improve skin wound healing, probably due to the synergistic effect of its components, mainly polyphenols, in different steps of the wound-healing process. It should be noted this is the first time that the wound-healing activity of a Mexican propolis has been evaluated.

Inhibition of proliferation, migration, and adhesion of skin fibroblasts by enzymatic poly(gallic acid) grafted with L-Arginine, migration, and adhesion of skin fibroblasts by enzymatic poly(gallic acid) grafted with L-Arginine.

Psoriasis and atopic dermatitis (AD) are characterized by enhanced skin inflammation, which results in hyperproliferation and the recruitment of immune cells into the skin. For that reason, it is needed a chemical capable to reduce cell proliferation and the recruitment of cells. The search for new molecules for therapeutic skin treatment mainly focuses on the antioxidant and anti-inflammatory properties, highlighting the rheological properties of polymeric polypeptides. We studied L-arginine (L-Arg) grafted (-g-) to enzymatic poly(gallic acid) (PGAL). The latter is a multiradical antioxidant with greater properties and thermal stability. The derivative was enzymatically polymerized in an innocuous procedure. The poly(gallic acid)-g-L-Arg molecule (PGAL-g-L-Arg) inhibits bacterial strains which also have been involved in the progression of psoriasis and AD. However, it is important to analyze their biological effect on skin cells. The cell viability was analyzed by calcein/ethidium homodimer assays and crystal violet. The proliferation and cell attachment were determined by a curve of time and quantitation of the optical density of crystal violet. To analyze the cell migration a wound-healing assay was performed. This synthesis demonstrates that it is not cytotoxic at high concentrations (250 µg/mL). We observed a decrease in the proliferation, migration, and adhesion of dermal fibroblasts in vitro but the compound could not avoid the increase of reactive oxygen species in the cell. Based on our findings, PGAL-g-L-Arg is a promising candidate for treating skin diseases such as psoriasis and AD where decreasing the proliferation and cell migration could help to avoid inflammation.

Protease-catalyzed synthesis of α-poly-L-Lysine and amphiphilic poly(L-lysine-co-L-phenylalanine) in a neat non-toxic organic solvent.

Subtilisin Carlsberg (alkaline protease from Bacillus licheniformis) catalyzes the syntheses of high molecular weights (ca. 20 KDa) cationic α-poly-L-lysine and amphiphilic poly(α-L-lysine-co-L-phenylalanine) in neat organic solvent. The synthesis is conducted in liquid 1,1,1,2-tetrafluoroethane solvent, which is a hydrophobic non-toxic gas that does not deplete the ozone layer and approved for pharmaceutical applications. Solubility of substrates and adequate protease activity in this system with low water environment limits the reaction of hydrolysis of the growing peptide chains. The pressurization of this organic compressed fluid to liquid has low-pressure requirements (25 bar, 40 ºC), and its complete evaporation at atmospheric pressure after completing the reaction ensures solvent-free residues in products. The resulting polypeptides present null cytotoxicity according to MTT and NR analyses, as well as Calcein/EthD-1 assay in human cells.

HLA-B27 may modulate the interaction between ERAP1 polymorphisms and smoking in ankylosing spondylitis patients.

BACKGROUND: Ankylosing spondylitis (AS) is an autoimmune disease that affects the enthesis and synovial membrane of the spine, the sacroiliac vertebrae and peripheral joints. Genetic susceptibility to AS is mainly due to the presence of the HLA-B*27 (B27) allele, and endoplasmic reticulum aminopeptidase-1 (ERAP-1) plays a key role in antigen processing and presentation to HLA class I molecules. Tobacco consumption is one of the main environmental factors involved in the pathogenesis of various diseases, including AS. The objective of the present study was to evaluate the association and the interactive effects of variants of the ERAP1 gene with smoking in modulating the risk of AS. METHODS AND RESULTS: A case-control study in the Mexican population. The association of two functional variants of the ERAP1 gene (rs30187 and rs27044) in patients with AS was analyzed by the allelic discrimination method using TaqMan probes. B27 was typified by PCR-SSP. The interaction between the variants of ERAP1 and B27 and smoking was assessed using the multifactorial dimensionality reduction (MDR) method. There was no significant association of the two variants of ERAP1 in the cases compared with the controls (P > 0.05); however, a strong interaction between the variants and smoking could be demonstrated, with entropy values of 4.97% for rs30187 and 5.13% for rs27044. In addition, these interaction effects were increased in patients carrying the B27 allele. CONCLUSIONS: The rs30187 and rs27044 variants of the ERAP1 gene appear to potentiate the effect of smoking in patients with AS carrying the B27 allele.

Radiation-induced graft polymerization of elastin onto polyvinylpyrrolidone as a possible wound dressing.

The purpose of our study was to obtain new wound dressings in the form of hydrogels that promote wound healing taking advantage of the broad activities of elastin (ELT) in physiological processes. The hydrogel of ELT and polyvinylpyrrolidone (PVP; ELT-PVP) was obtained by cross-linking induced by gamma irradiation at a dose of 25 kGy. The physicochemical changes attributed to cross-linking were analyzed through scanning electron microscopy (SEM), infrared spectroscopy analysis with Fourier transform (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Furthermore, we performed a rheological study to determine the possible changes in the fluidic macroscopic properties produced by the cross-linking method. Finally, we accomplished viability and proliferation analyses of human dermal fibroblasts in the presence of the hydrogel to evaluate its biological characteristics. The hydrogel exhibited a porous morphology, showing interconnected porous with an average pore size of 16 ± 8.42 µm. The analysis of FTIR, DSC, and TGA revealed changes in the chemical structure of the ELT-PVP hydrogel after the irradiation process. Also, the hydrogel exhibited a rheological behavior of a pseudoplastic and thixotropic fluid. The hydrogel was biocompatible, demonstrating high cell viability, whereas ELT presented low biocompatibility at high concentrations. In summary, the hydrogel obtained by gamma irradiation revealed the appropriate morphology to be applied as a wound dressing. Interestingly, the hydrogel exhibited a higher percentage of cell viability compared with ELT, suggesting that the cross-linking of ELT with PVP is a suitable strategy for biological applications of ELT without generating cellular damage.

Gamma radiation-induced grafting of poly(2-aminoethyl methacrylate) onto chitosan: A comprehensive study of a polyurethane scaffold intended for skin tissue engineering.

A novel brush-like poly(2-aminoethyl methacrylate) (PAEMA) was grafted onto chitosan (CS) through gamma radiation-induced polymerization. The copolymer (CS-g-PAEMA) was used to prepare a sodium acetate leached poly(urethane-urea) scaffold. The above derivatives were developed, synthesized, and characterized to meet the specific characteristics of biomaterials. The results revealed that this method is an easy and successful route for grafting PAEMA onto CS. The feasibility of preparing a CS-g-PAEMA polyurethane foam was confirmed by mechanical, morphometric, spectroscopic, and cytotoxic studies. The scaffold showed high biocompatibility both in vitro and in vivo. The first experiment proved that CS-based polyurethane efficiently allows the dynamic culturing of human fibroblast cells. Additionally, an in vivo study in a murine model indicated a complete integration of the scaffold to surrounding subcutaneous tissue as supported by the histological and histochemical assessments. The aforementioned results support the use of CS-g-PAEMA poly(saccharide-urethane) as a model of in vitro-engineered skin.

Gamma radiation-induced grafting of n-hydroxyethyl acrylamide onto poly(3-hydroxybutyrate): A companion study on its polyurethane scaffolds meant for potential skin tissue engineering applications.

This study aimed at investigating the synthesis, characterization, and search for a biotechnological application proposal for poly [(R)-3-hydroxybutyric acid] (PHB) grafted with the n-hydroxyethyl acrylamide (HEAA) monomer. The novel copolymer was prepared by 60Co gamma radiation-induced-graft polymerization. The effect of different solvents in the graft polymerization; the degree of grafting, crystallinity, and hydrophilicity; the morphology and the thermal properties were evaluated. The polyurethane fabricated from the grafted PHB was suggested as a scaffold. The enzymatic degradation behavior and the spectroscopic, morphological, mechanical, and biological properties of the composites were assessed. According to the results, the successful grafting of HEAA onto PHB was verified. The grafting was significantly affected by the type of solvent employed. A decreased crystallinity and increased hydrophilicity of the graft copolymer, concerning the PHB, was found. An increased roughness was observed in the morphology of the polymer after grafting. The thermodynamic parameters, except for the glass transition temperature, also decreased for the synthetic biopolymer. The intended use of these scaffolds for skin tissue engineering was supported by a proper degradability and degree of porosity, improved mechanical properties, the optimal culture of human fibroblasts, and its transfection with a plasmid vector containing an enhanced green fluorescent protein.

Impact of cadmium toxicity on cartilage loss in a 3D in vitro model.

Osteoarthritis (OA) is the gradual loss of articular cartilage and decrease in subchondral space. One of the risk factors Exposure to cadmium (Cd) through tobacco smoke has been identified as a major OA risk factor. There are no reports addressing the role of Cd in OA progression at the molecular level. Our findings revealed that Cd can promote the activation of metalloproteinases (MMP1, MMP3, MMP9 y MMP13), affecting the expression of COL2A1 and ACAN, and decreasing the presence of glycosaminoglycans and proteoglycans through an inflammatory response related to IL-1ß y a IL-6, as well as oxidative by producing ROS like O2-• and H2O2. In conclusion, our findings suggest a cytotoxic role of Cd in the articular cartilage, which could affect OA development.

Fast cyclical-decellularized trachea as a natural 3D scaffold for organ engineering.

Commonly reported decellularization protocols for trachea may take up from several weeks to months in order to remove the cellular materials. Two years ago, we significantly reduced the time of decellularization trachea process using trypsin. Despite the positive outcome, the protocol was useful to produce 5 cm graft length, an unsuitable length graft for most patients with tracheal disorders. In this work we improved the decellularization procedure for longer sections up to 10 cm without considerable extension in the necessary time process (2 weeks). Herein, for the first time, we completely describe and characterize the process for pig tracheal bioactive scaffolds. Histological and molecular biology analysis demonstrated effective removal of cellular components and nuclear material, which was also confirmed by the Immunohistochemical (IHC) analysis of the major histocompatibility complexes (MHCs) and DNA stain by 4'-6-diamidino-2-phenylindole (DAPI). The images and data obtained from scanning electron microscopy (SEM) and thermal analysis showed conservation of the hierarchical structures of the tracheal extracellular matrix (ECM), the biomechanical tests showed that decellularization approach did not lead to a significant alteration on the mechanical properties. In this paper, we demonstrate that the proposed cyclical-decellularization protocol allowed us to obtain a non-immunological 10 cm natural tracheal scaffold according to the in vivo immunological assessment. Furthermore, the recellularization of the matrix was successfully achieved by demonstrating first-stage cellular differentiation from stem cells to chondrocytes expressed by the SOX9 transcription factor; this organ-engineered tracheal matrix has the potential to act as a suitable template for organ regeneration.

Poly(3-hydroxybutyrate) graft copolymer dense membranes for human mesenchymal stem cell growth

Background: The use of novel materials as an artificial extracellular matrix for stem cell growth is a current strategy of increasing interest for regenerative medicine. Here, we prepare thermal-remolded membrane scaffolds from poly(3-hydroxybutyrate) grafted with 2-amino-ethyl methacrylate hydrochloride. However, it is unclear whether these membranes are useful for tissue engineering. Results: The mechanical properties, tribology, and morphology of the dense membranes were assessed. The results show that tensile strain at break and roughness of the compressed membrane decrease with increasing graft degree. Moreover, graft copolymer membranes showed lower resistance to scratching, greater degree of swelling and higher brittleness than un-grafted P(3HB) films. Thus, it effectively supports the growth of dermal fibroblast, as demonstrated by epifluorescence microscopy. Conclusions: It is concluded that the developed membrane can be properly used in is the restoration of skin tissue. How to cite: González-Torres M, Sánchez-Sánchez R, Solís-Rosales SG, et al. Poly(3-hydroxybutyrate) graft copolymer dense membranes for human mesenchymal stem cell growth.

Silver-pig skin nanocomposites and mesenchymal stem cells: suitable antibiofilm cellular dressings for wound healing.

BACKGROUND: Treatment of severe or chronic skin wounds is an important challenge facing medicine and a significant health care burden. Proper wound healing is often affected by bacterial infection; where biofilm formation is one of the main risks and particularly problematic because it confers protection to microorganisms against antibiotics. One avenue to prevent bacterial colonization of wounds is the use of silver nanoparticles (AgNPs); which have proved to be effective against non-multidrug-resistant and multidrug-resistant bacteria. In addition, the use of mesenchymal stem cells (MSC) is an excellent option to improve wound healing due to their capability for differentiation and release of relevant growth factors. Finally, radiosterilized pig skin (RPS) is a biomatrix successfully used as wound dressing to avoid massive water loss, which represents an excellent carrier to deliver MSC into wound beds. Together, AgNPs, RPS and MSC represent a potential dressing to control massive water loss, prevent bacterial infection and enhance skin regeneration; three essential processes for appropriate wound healing with minimum scaring. RESULTS: We synthesized stable 10 nm-diameter spherical AgNPs that showed 21- and 16-fold increase in bacteria growth inhibition (in comparison to antibiotics) against clinical strains Staphylococcus aureus and Stenotrophomonas maltophilia, respectively. RPS samples were impregnated with different AgNPs suspensions to develop RPS-AgNPs nanocomposites with different AgNPs concentrations. Nanocomposites showed inhibition zones, in Kirby-Bauer assay, against both clinical bacteria tested. Nanocomposites also displayed antibiofilm properties against S. aureus and S. maltophilia from RPS samples impregnated with 250 and 1000 ppm AgNPs suspensions, respectively. MSC were isolated from adipose tissue and seeded on nanocomposites; cells survived on nanocomposites impregnated with up to 250 ppm AgNPs suspensions, showing 35% reduction in cell viability, in comparison to cells on RPS. Cells on nanocomposites proliferated with culture days, although the number of MSC on nanocomposites at 24 h of culture was lower than that on RPS. CONCLUSIONS: AgNPs with better bactericide activity than antibiotics were synthesized. RPS-AgNPs nanocomposites impregnated with 125 and 250 ppm AgNPs suspensions decreased bacterial growth, decreased biofilm formation and were permissive for survival and proliferation of MSC; constituting promising multi-functional dressings for successful treatment of skin wounds.

Virulence in Mice of a Toxoplasma gondii Type II Isolate Does Not Correlate With the Outcome of Experimental Infection in Pregnant Sheep.

Toxoplasma gondii is an apicomplexan parasite that infects almost all warm-blooded animals. Little is known about how the parasite virulence in mice extrapolates to other relevant hosts. In the current study, in vitro phenotype and in vivo behavior in mice and sheep of a type II T. gondii isolate (TgShSp1) were compared with the reference type II T. gondii isolate (TgME49). The results of in vitro assays and the intraperitoneal inoculation of tachyzoites in mice indicated an enhanced virulence for the laboratory isolate, TgME49, compared to the recently obtained TgShSp1 isolate. TgShSp1 proliferated at a slower rate and had delayed lysis plaque formation compared to TgME49, but it formed more cyst-like structures in vitro. No mortality was observed in adult mice after infection with 1-105 tachyzoites intraperitoneally or with 25-2,000 oocysts orally of TgShSp1. In sheep orally challenged with oocysts, TgME49 infection resulted in sporadically higher rectal temperatures and higher parasite load in cotyledons from ewes that gave birth and brain tissues of the respective lambs, but no differences between these two isolates were found on fetal/lamb mortality or lesions and number of T. gondii-positive lambs. The congenital infection after challenge at mid-pregnancy with TgShSp1, measured as offspring mortality and vertical transmission, was different depending on the challenged host. In mice, mortality in 50% of the pups was observed when a dam was challenged with a high oocyst dose (500 TgShSp1 oocysts), whereas in sheep infected with the same dose of oocysts, mortality occurred in all fetuses. Likewise, mortality of 9 and 27% of the pups was observed in mice after infection with 100 and 25 TgShSp1 oocysts, respectively, while in sheep, infection with 50 and 10 TgShSp1 oocysts triggered mortality in 68 and 66% of the fetuses/lambs. Differences in vertical transmission in the surviving offspring were only found with the lower oocyst doses (100% after infection with 10 TgShSp1 oocysts in sheep and only 37% in mice after infection with 25 TgShSp1 oocysts). In conclusion, virulence in mice of T. gondii type II isolates may not be a good indicator to predict the outcome of infection in pregnant sheep.

Cytoprotective effect of the enzyme-mediated polygallic acid on fibroblast cells under exposure of UV-irradiation.

The poly(gallic acid), produced by laccase-mediated oxidation of gallic acid in aqueous media (pH5.5) to attain a novel material with well-defined molecular structure and high water solubility (500mg/mL at 25°C), has been investigated to understand its potential biological activities. In this regard, a biomedical approach based on cytoprotective effect on human fibroblast cells exposed to UV-irradiation in the presence of the polymer has been demonstrated. The results also shows that 200µg/mL of poly(gallic acid) inhibits the growth and migration of dermal fibroblasts and cancer cell lines without affecting cell viability. Poly(gallic acid) pretreatment with 10µg/mL protects dermal fibroblasts from UV induced cell death and additionally, the cytoprotective effect reduce ROS presence in the cells. This property can be correlated with the antioxidant power (IC50 of 23.5µg/mL) of this novel material, which was ascertained by electronic paramagnetic resonance spectroscopy and spectrophotometrically. Additionally, the antimicrobial activity of this material was corroborated with the inhibition of Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 29212) strains (MIC=400mg/mL) common bacteria found in hospitals.

Generation of Two Biological Wound Dressings as a Potential Delivery System of Human Adipose-Derived Mesenchymal Stem Cells.

Human adipose-derived mesenchymal stem cells (hADMSCs) are believed to be potential key factors for starting the regenerative process after tissue injury. However, an efficient method of delivering these regenerative cells to an external wound site is still lacking. Human amnion and pig skin have long been used as skin wound dressings for the treatment of burns and other skin lesions. Herein, we present the generation of two constructs using these two biomaterials as effective scaffolds for the culture of hADMSCs. It was found that hADMSCs seeded onto radiosterilized human amnion and pig skin are viable and proliferate. These cells are able to migrate over these scaffolds as demonstrated by using time-lapse microscopy. In addition, the scaffolds induce hADMSCs to secrete interleukin-10, an important negative regulator of inflammation, and interleukin-1ß, a proinflammatory protein. The interplay between these two proteins has been proven to be vital for a balanced restoration of all necessary tissues. Thus, radiosterilized human amnion and pig skin are likely suitable scaffolds for delivery of hADMSCs transplants that could promote tissue regeneration in skin injuries like patients with burn injuries.

Biocompatibility of human auricular chondrocytes cultured onto a chitosan/polyvynil alcohol/epichlorohydrin-based hydrogel for tissue engineering application / Biocompatibilidad de condrocitos humanos cultivados sobre un hidrogel a base de quitosano/alcohol polivnílico/epiclorhidrina para aplicación en ingeniería de tejidos

Tissue engineering (TE) has become an alternative for auricular reconstruction based on the combination of cells, molecular signals and biomaterials. Scaffolds are biomaterials that provide structural support for cell attachment and subsequent tissue development. Ideally, a scaffold should have characteristics such as biocompatibility and bioactivity to adequate support cell functions. Our purpose was to evaluate biocompatibility of microtic auricular chondrocytes seeded onto a chitosan-polyvinyl alcohol-epichlorohydrin (CS-PVA-ECH) hydrogel to propose this material as a scaffold for tissue engineering application. After being cultured onto CS-PVA-ECH hydrogels, auricular chondrocytes viability was up to 81%. SEM analysis showed cell attachment and extracellular matrix formation that was confirmed by IF detection of type II collagen and elastin, the main constituents of elastic cartilage. Expression of elastic cartilage molecular markers during in vitro expansion and during culture onto hydrogels allowed confirming auricular chondrocyte phenotype. In vivo assay of tissue formation revealed generation of neotissues with similar physical characteristics and protein composition to those found in elastic cartilage. According to our results, biocompatibility of the CS-PVA-ECH hydrogel makes it a suitable scaffold for tissue engineering application aimed to elastic cartilage regeneration.

La ingeniería de tejidos (TE) es una alternativa para la reconstrucción auricular basada en la combinación de células, señales moleculares y biomateriales. Los andamios fabricados con biomateriales brindan un soporte estructural que favorece la adhesión cellular y el desarrollo del tejido. Un andamio debe poseer características como biocompatibilidad y bioactividad para soportar adecuadamente funciones celulares. Nuestro objetivo fue evaluar la biocompatibilidad de condrocitos auriculares de microtia cultivados sobre un hidrogel a base de quitosano-alcohol polivinílico-epiclorhidrina (CS-PVA-ECH) y proponerlo como andamio con aplicaciones en ingeniería de tejidos. La viabilidad de los condrocitos auriculares es superior al 81% después de ser cultivados sobre el hidrogel. El análisis por SEM reveló la unión celular y formación de matriz extracellular sobre el hidrogel; confirmada mediante detección por IF de colágena tipo II y elastina. La expresión de marcadores moleculares durante la expansión in vitro y el cultivo sobre los hidrogeles confirmaron el fenotipo condral. El ensayo de formación de tejido in vivo demostró la generación de neotejidos con características físicas y composición similar al cartílago elástico. Nuestros resultados indican que la biocompatibilidad del hidrogel de CS-PVA-ECH lo hace un andamio adecuado para aplicaciones en ingeniería de tejidos enfocadas a regeneración de cartílago elástico.