Chitosan membranes incorporating Aloe vera glycolic extract with joint synthesis of silver nanoparticles for the treatment of skin lesions.

New wound dressings based on polymeric membranes have been widely exploited for clinical applications to assist in the healing process and prevent additional complications (e.g., bacterial infections). Here we propose the development of a new production method of polymeric membranes based on chitosan, incorporating glycolic extract of Aloe vera with joint synthesis of silver nanoparticles for use as a new bioactive dressing. The membranes were obtained by casting technique, and their morphological, physicochemical characteristics, degree of swelling, degradation profile and antimicrobial activity evaluated. Morphological analyzes confirmed the synthesis and presence of silver nanoparticles in the polymeric membrane. The chemical compatibility between the materials was demonstrated through thermal analysis (TGA and DSC) combined with ATR-FTIR tests, showing the complexation of the membranes (Mb-Ch-Ex.Av-NPs). All membranes were characterized as hydrophilic material (with a contact angle (Ó©) < 90°); however, the highest degree of swelling was obtained for the chitosan. (Mb-Ch) membrane (69.91 ± 5.75%) and the lowest for Mb-Ch-Ex.Av-NPs (26.62 ± 8.93%). On the other hand, the degradation profile was higher for Mb-Ch-Ex.Av-NPs (77.85 ± 7.51%) and lower for Mb-Ch (57.60 ± 2.29%). The manufactured bioactive dressings showed activity against Escherichia coli and Staphylococcus aureus. Our work confirmed the development of translucent and flexible chitosan-based membranes, incorporating Aloe vera glycolic extract with joint synthesis of silver nanoparticles for use as a new bioactive dressing, with proven antimicrobial activity.

Psidium guajava L. phenolic compound-reinforced lamellar scaffold for tracheal tissue engineering.

The aim of this work was to develop a dense lamellar scaffold, as a biomimetic material with potential applications in the regeneration of tracheal tissue after surgical tumor resection. The scaffolds were produced by plastic compression technique, exploiting the use of total phenolic compounds (TPC) from Psidium guajava Linn as a potential cross-linking agent in a polymeric mixture based on collagen (COL), silk fibroin (SF), and polyethylene glycol 400 (PEG 400). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) confirmed the chemical interactions between the polymers and the cross-linking of TPC between COL and SF. Morphological analyses showed scaffolds with porosity, interconnectivity, and a porous surface structure with a gyroid-like geometry. The analysis of the anisotropic degree resulted in anisotropic structures (0.1% TFC and 0.3% TFC) and an isotropic structure (0.5% TFC). In the mechanical properties, it was evidenced greater resistance for the 0.3% TFC formulation. The addition of TPC percentages did not result in a significant difference (p > 0.05) in swelling capacity and disintegration rate. The results confirmed that TPC were able to modulate the morphological, morphometric, and mechanical properties of scaffolds. Thus, this study describes a potential new material to improve the regeneration of major tracheal structures after surgical tumor removal.

Nanomaterials-combined methacrylated gelatin hydrogels (GelMA) for cardiac tissue constructs.

Among non-communicable diseases, cardiovascular diseases are the most prevalent, accounting for approximately 17 million deaths per year. Despite conventional treatment, cardiac tissue engineering emerges as a potential alternative for the advancement and treatment of these patients, using biomaterials to replace or repair cardiac tissues. Among these materials, gelatin in its methacrylated form (GelMA) is a biodegradable and biocompatible polymer with adjustable biophysical properties. Furthermore, gelatin has the ability to replace and perform collagen-like functions for cell development in vitro. The interest in using GelMA hydrogels combined with nanomaterials is increasingly growing to promote the responsiveness to external stimuli and improve certain properties of these hydrogels by exploring the incorporation of nanomaterials into these hydrogels to serve as electrical signaling conductive elements. This review highlights the applications of electrically conductive nanomaterials associated with GelMA hydrogels for the development of structures for cardiac tissue engineering, by focusing on studies that report the combination of GelMA with nanomaterials, such as gold and carbon derivatives (carbon nanotubes and graphene), in addition to the possibility of applying these materials in 3D tissue engineering, developing new possibilities for cardiac studies.

Nanotechnology-Based Dressings for Wound Management.

Wound healing is known to be a complicated and intricate process and commonly classified as chronic or acute. Patients with chronic wounds are of public health concern, and require more attention onto skin lesions, including atopic dermatitis. Despite being a natural process, healing can be impaired by existing chronic de diseases such as diabetes, for example. Recently, wound dressings based in nanotechnology systems have emerged as a viable option to improve the healing process. Current advances in nanotechnology-based systems to release growth factors and bioactive agents represent a great opportunity to develop new therapies for wound treatments. It is essential that healthcare professionals understand the key processes involved in the healing cascade, to maximize care with these patients and minimize the undesirable outcomes of non-healing wounds. Therefore, this review aims to summarize the healing process phases and provide a general overview of dressings based in nanotechnology using biomaterials for the release of active agents in wound site.

Rutin-Functionalized Multi-Walled Carbon Nanotubes: Molecular Docking, Physicochemistry and Cytotoxicity in Fibroblasts.

Multi-Walled Carbon Nanotubes (MWCNT) have been functionalized with rutin through three steps (i. reaction step; ii. purification step; iii. drying step) and their physicochemical properties investigated with respect to morphological structure, thermal analysis, Fourier Transform Infrared Spectroscopy (FTIR), and cytotoxicity. The molecular docking suggested the rutin-functionalized MWCNT occurred by hydrogen bonds, which was confirmed by FTIR assays, corroborating the results obtained by thermal analyses. A tubular shape, arranged in a three-dimensional structure, could be observed. Mild cytotoxicity observed in 3T3 fibroblasts suggested a dose-effect relationship after exposure. These findings suggest the formation of aggregates of filamentous structures on the cells favoring the cell penetration.

Curcumin encapsulation in nanostructures for cancer therapy: A 10-year overview.

Curcumin (CUR) is a phenolic compound present in some herbs, including Curcuma longa Linn. (turmeric rhizome), with a high bioactive capacity and characteristic yellow color. It is mainly used as a spice, although it has been found that CUR has interesting pharmaceutical properties, acting as a natural antioxidant, anti-inflammatory, antimicrobial, and antitumoral agent. Nonetheless, CUR is a hydrophobic compound with low water solubility, poor chemical stability, and fast metabolism, limiting its use as a pharmacological compound. Smart drug delivery systems (DDS) have been used to overcome its low bioavailability and improve its stability. The current work overviews the literature from the past 10 years on the encapsulation of CUR in nanostructured systems, such as micelles, liposomes, niosomes, nanoemulsions, hydrogels, and nanocomplexes, emphasizing its use and ability in cancer therapy. The studies highlighted in this review have shown that these nanoformulations achieved higher solubility, improved tumor cytotoxicity, prolonged CUR release, and reduced side effects, among other interesting advantages.

ß-Cyclodextrin/Isopentyl Caffeate Inclusion Complex: Synthesis, Characterization and Antileishmanial Activity.

Isopentyl caffeate (ICaf) is a bioactive ester widely distributed in nature. Our patented work has shown promising results of this molecule against Leishmania. However, ICaf shows poor solubility, which limits its usage in clinical settings. In this work, we have proposed the development of an inclusion complex of ICaf in ß-cyclodextrin (ß-CD), with the aim to improve the drug solubility, and thus, its bioavailability. The inclusion complex (ICaf:ß-CD) was developed applying three distinct methods, i.e., physical mixture (PM), kneading (KN) or co-evaporation (CO) in different molar proportions (0.25:1, 1:1 and 2:1). Characterization of the complexes was carried out by thermal analysis, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and molecular docking. The ICaf:ß-CD complex in a molar ratio of 1:1 obtained by CO showed the best complexation and, therefore, was selected for further analysis. Solubility assay showed a marked improvement in the ICaf:ß-CD (CO, 1:1) solubility profile when compared to the pure ICaf compound. Cell proliferation assay using ICaf:ß-CD complex showed an IC50 of 3.8 and 2.7 µg/mL against L. amazonesis and L. chagasi promastigotes, respectively. These results demonstrate the great potential of the inclusion complex to improve the treatment options for visceral and cutaneous leishmaniases.

Cachexia: Pathophysiology and Ghrelin Liposomes for Nose-to-Brain Delivery.

Cachexia, a severe multifactorial condition that is underestimated and unrecognized in patients, is characterized by continuous muscle mass loss that leads to progressive functional impairment, while nutritional support cannot completely reverse this clinical condition. There is a strong need for more effective and targeted therapies for cachexia patients. There is a need for drugs that act on cachexia as a distinct and treatable condition to prevent or reverse excess catabolism and inflammation. Due to ghrelin properties, it has been studied in the cachexia and other treatments in a growing number of works. However, in the body, exogenous ghrelin is subject to very rapid degradation. In this context, the intranasal release of ghrelin-loaded liposomes to cross the blood-brain barrier and the release of the drug into the central nervous system may be a promising alternative to improve its bioavailability. The administration of nose-to-brain liposomes for the management of cachexia was addressed only in a limited number of published works. This review focuses on the discussion of the pathophysiology of cachexia, synthesis and physiological effects of ghrelin and the potential treatment of the diseased using ghrelin-loaded liposomes through the nose-to-brain route.

Bilayer Mucoadhesive Buccal Film for Mucosal Ulcers Treatment: Development, Characterization, and Single Study Case.

The formation of mucosal ulcers is an end result of epithelial damage, and it occurs due to some specific causes, such as trauma, aphthous stomatitis, lichen planus and lichenoid reactions, cytotoxic effects of chemotherapy and radiation, and drug-induced hypersensitivity reactions and malignant settings. This study focused on films for target drug delivery with respect to the treatment of the diseases of the oral mucosa, specifically mucositis. The results of a single clinical study as a pre-experimental design was performed and followed up to the outcome until 30 days. The polymeric film was prepared in a mucoadhesive bilayer structure: the basal layer with lidocaine HCl had a faster release than the apical layer with benzydamine HCl and N-acetyl-cysteine. Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and SEM characterized the physical-chemical and morphological properties. The cell viability and cytotoxicity were evaluated in cell line MCF7. The transport mechanism of the solvent (swelling) and the drugs in the basal or apical layer (drug release) was explained with mathematical models. To evaluate the effect of movement inside the mouth, the folding endurance was determined. The mucoadhesive bilayer film is biologically safe and stimulates cellular proliferation. A single study in vivo demonstrated the therapeutic effect of the mucoadhesive bilayer film in buccal mucositis.

Alternative Cutaneous Substitutes Based on Poly(l-co-d,l-lactic acid-co-trimethylene carbonate) with Schinus terebinthifolius Raddi Extract Designed for Skin Healing.

The search for new therapies and drugs that act as topical agents to relieve pain and control the inflammatory processes in burns always attracted interest in clinical trials. As an alternative to synthetic drugs, natural extracts are useful in the development of new strategies and formulations for improving the quality of life. The aim of this study was to develop a wound dressing using poly(l-co-d,l-lactic acid-co-trimethylene carbonate) (PLDLA-TMC) containing Schinus terebinthifolius Raddi (S.T.R.). S.T.R. is a native Brazilian plant known for its strong anti-inflammatory responses. The membrane of PLDLA-TMC + S. terebinthifolius Raddi was prepared at different concentrations of S.T.R. (5, 10, 15, and 50%). The Fourier transform infrared results showed no change in the PLDLA-TMC spectrum after S.T.R. addition, whereas the swelling test showed changes only in PLDLA-TMC + S.T.R. at 50%. The wettability measurements showed a mass loss due to the decrease in the contact angle in all samples after the S.T.R. addition in the polymer, whereas the S.T.R. release test showed a linear delivery pattern. The scanning electron microscopy analysis showed that S.T.R. was homogeneously distributed at only 5 and 10%. Tensile tests demonstrated an increase in Young's modulus and a reduction in the elongation till rupture of PLDLA-TMC after the addition of S.T.R. The biocompatibility in vitro evaluation with rat fibroblast cells seeded in the membranes of PLDLA-TMC + S.T.R. showed that although S.T.R. interfered in cell morphology, all concentrations tested showed that cells were able to adhere and proliferate during 7 days. Thus, S.T.R. at 50% was chosen to be tested for in vivo trials. The histological and immunohistochemistry results revealed an accelerated skin healing at 7 days after controlled secondary burns were introduced in the dorsal skin, with a striking total recovery of the epidermis and high rates of molecular activation of cell proliferation. Due to the known biocompatibility properties of PLDLA-TMC and its stable release of S.T.R., we strongly recommend S.T.R.-containing PLDLA-TMC as a curative device to favor skin healing.

Praziquantel-Solid Lipid Nanoparticles Produced by Supercritical Carbon Dioxide Extraction: Physicochemical Characterization, Release Profile, and Cytotoxicity.

Solid lipid nanoparticles (SLNs) can be produced by various methods, but most of them are difficult to scale up. Supercritical fluid (SCF) is an important tool to produce micro/nanoparticles with a narrow size distribution and high encapsulation efficiency. The aim of this work was to produce cetyl palmitate SLNs using SCF to be loaded with praziquantel (PZQ) as an insoluble model drug. The mean particle size (nm), polydispersity index (PdI), zeta potential, and encapsulation efficiency (EE) were determined on the freshly prepared samples, which were also subject of Differential Scanning Calorimetry (DSC), Fourier-Transform Infrared Spectroscopy (FTIR), drug release profile, and in vitro cytotoxicity analyses. PZQ-SLN exhibited a mean size of ~25 nm, PdI ~ 0.5, zeta potential ~-28 mV, and EE 88.37%. The DSC analysis demonstrated that SCF reduced the crystallinity of cetyl palmitate and favored the loading of PZQ into the lipid matrices. No chemical interaction between the PZQ and cetyl palmitate was revealed by FTIR analysis, while the release or PZQ from SLN followed the Weibull model. PZQ-SLN showed low cytotoxicity against fibroblasts cell lines. This study demonstrates that SCF may be a suitable scale-up procedure for the production of SLN, which have shown to be an appropriate carrier for PZQ.

Hyaluronic acid behavior in oral administration and perspectives for nanotechnology-based formulations: A review.

Hyaluronic acid (HA) is a ubiquitous polysaccharide with diverse biological functions. Is known that in the intestinal epithelium, the exogenous HA of molar mass ≥105 Da orally administered antagonizes TLR4 overexpression resulting from dysbiosis and promotes immunomodulation in multifactorial crosstalk, thus helping to treat or to prevent injuries. As macromolecules mediate cell signaling, the three-dimensional structure of HA plays a vital role in those functions. Introducing HA in terms of its molecular structure, its spatial architecture as dependent on pH, concentration and molar mass, occurrence, biological functions and turnover in the tissues, this review addresses the HA in the gastrointestinal system, the molecular dynamics of intestinal uptake and signaling, immunomodulation at intestinal and systemic levels and HA fate to other tissues. Finally, at the light of these behaviors, a nanotechnological approach is presented as progress in the field of the oral HA administration and discussed with perspectives for future developments.

Crystalline Ethylene Oxide and Propylene Oxide Triblock Copolymer Solid Dispersion Enhance Solubility, Stability and Promoting Time- Controllable Release of Curcumin.

AIMS AND BACKGROUND: The design and development of an effective medicine are, however, often faced with a number of challenges. One of them is the close relationship of drug's bioavailability with solubility, dissolution rate and permeability. The use of curcumin's (CUR) therapeutic potential is limited by its poor water solubility and low chemical stability. The purpose was to evaluate the effect of polymer and solid dispersion (SD) preparation techniques to enhance the aqueous solubility, dissolution rate and stability of the CUR. The recent patents on curcumin SD were reported as (i) curcumin with polyvinylpyrrolidone (CN20071 32500 20071214, WO2006022012 and CN20151414227 20150715), (ii) curcumin-zinc/polyvinylpyrrolidone (CN20151414227 20150715), (iii) curcumin-poloxamer 188 (CN2008171177 20080605), (iv) curcumin SD prepared by melting method (CN20161626746-20160801). MATERIALS AND METHODS: SD obtained by co-preciptation or microwave fusion and the physical mixture of CUR with Poloxamer-407 (P-407), Hydroxypropylmetylcellulose-K4M (HPMC K4M) and Polyvinylpyrrolidone-K30 (PVP-K30) were prepared at the ratios of 1:2; 1:1 and 2:1. The samples were evaluated by solubility, stability, dissolution rate and characterized by SEM, PXRD, DSC and FTIR. RESULTS: The solubility, stability (pH 7.0) and dissolution rate were significantly greater for SD (CUR:P-407 1:2). The PXRD,SEM and DSC indicated a change in the crystalline state of CUR. The enhancement of solubility was dependent on a combination of factors including the weight ratio, preparation techniques and carrier properties. The drug release data fitted well with the Weibull equation, indicating that the drug release was controlled by diffusion, polymer relaxation and erosion occurring simultaneously. CONCLUSION: Thus, these SDs, specifically CUR:P-407 1:2 w/w, can overcome the barriers of poor bioavailability to reap many beneficial properties.

Association of Silver Nanoparticles and Curcumin Solid Dispersion: Antimicrobial and Antioxidant Properties.

The last century, more precisely after 1945, was marked by major advances in the treatment of infectious diseases which promoted a decrease in mortality and morbidity. Despite these advances, currently the development of antimicrobial resistance has been growing drastically and therefore there is a pressing need to search for new compounds. Silver nanoparticles (AgNps) have been demonstrating good antimicrobial activity against different bacteria, viruses, and fungi. Curcumin (CUR) extracted from rhizomes of Curcuma longa has a variety of applications including antiinflammatory, antioxidant, and antibacterial agent. The association between silver nanoparticles and curcumin in a formulation can be a good alternative to control infectious diseases due the antimicrobial properties of both compounds. The objective of this work was to develop a formulation composed of a thermoresponsive gel-with antimicrobial and antioxidant properties due to the association of AgNps with PVP and PVA polymers. After AgNp synthesis, these were incorporated together with the previously prepared CUR/P407 (1:2) solid dispersion (SD) into a polymer dispersion of 20% P407 (thermosensitive gel). Our results showed that the association between the AgNps with CUR SD demonstrated good antioxidant activity as compared to the standard compound. Measures of MIC showed more efficacy against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) than for Gram-positive bacteria (Staphylococcus aureus). This association enhances antimicrobial activity against E. coli and P aeruginosa and added antioxidant value in formulations.

Production, stabilisation and characterisation of silver nanoparticles coated with bioactive polymers pluronic F68, PVP and PVA.

The increasing and alarming panorama of bacterial infections and associated morbidities that occur during medical and hospital procedures makes the development of technologies that aid in controlling such bacterial infections of utmost importance. Recent studies have shown that formulations with metal nanoparticles exhibit good antibacterial properties against a broad spectrum of microorganisms. Moreover, it was demonstrated that some biologically active polymeric materials, when applied in combination with chemical antimicrobial agents, enhance the therapeutic action of the latter. The research effort entertained herein aimed at the physico-chemical characterisation of silver nanoparticles obtained by chemical reduction, stabilised by bioactive polymers polyvinyl alcohol and polyvinylpyrrolidone, and further co-stabilised by pluronic F68. Scanning electron microscopy images of the nanoparticles produced, coated with different stabilisers, have shown that the chemical nature of the stabilisation effect promoted incorporation of pluronic in the nanoparticles and was closely related to an increase in the silver concentration in the nanoparticle samples obtained via energy-dispersive X-ray spectroscopy. The study described herein also shows that the nature of the stabiliser favours the interaction of pluronic F68 with samples containing silver nanoparticles.

Spotlight on Biomimetic Systems Based on Lyotropic Liquid Crystal.

The behavior of lyotropic biomimetic systems in drug delivery was reviewed. These behaviors are influenced by drug properties, the initial water content, type of lyotropic liquid crystals (LLC), swell ability, drug loading rate, the presence of ions with higher or less kosmotropic or chaotropic force, and the electrostatic interaction between the drug and the lipid bilayers. The in vivo interaction between LCC-drugs, and the impact on the bioavailability of drugs, was reviewed. The LLC with a different architecture can be formed by the self-assembly of lipids in aqueous medium, and can be tuned by the structures and physical properties of the emulsion. These LLC lamellar phase, cubic phase, and hexagonal phase, possess fascinating viscoelastic properties, which make them useful as a dispersion technology, and a highly ordered, thermodynamically stable internal nanostructure, thereby offering the potential as a sustained drug release matrix for drug delivery. In addition, the biodegradable and biocompatible nature of lipids demonstrates a minimum toxicity and thus, they are used for various routes of administration. This review is not intended to provide a comprehensive overview, but focuses on the advantages over non modified conventional materials and LLC biomimetic properties.

Study of the elemental composition of saliva of smokers and nonsmokers by X-ray fluorescence.

Cigarette smoking is a serious public health problem. According to data from the World Health Organization, it is estimated that currently more than 1.2 billion people worldwide do tobacco use and that smoking-related diseases are responsible for about 6 million deaths each. With attention to this, it is necessary to seek preventive and prognostic of trying to reduce these numbers and alert the public in general about the danger and the harm caused by its use. Thus, the objective of the research work undertaken was to evaluate and compare the chemical composition of collected saliva samples of smokers and nonsmokers by X-ray Fluorescence analyses. 32 individuals were selected, 16 of which used cigarette on a daily basis and the other 16 had never smoked. Saliva was collected with the help of a (sterile) disposable Pasteur pipette and samples sent to the Applied Nuclear Physics Laboratory at UNISO (LAFINAU), where analyzes were carried out. Individuals who agreed to participate in the study answered a questionnaire to define their profile of inclusion and signed an informed consent form (CEP Protocol no. 831.753 of 09/10/2014). The results clearly showed that there are differences in the concentrations of chemical elements in the saliva of smokers and non-smokers. The biggest discrepancies were found at concentrations of the chemical elements Sulfur, Phosphorus, Chlorine and Potassium, and smaller differences in the concentration of the elements Calcium, Manganese, Iron, Copper, Titanium, Vanadium and Nickel. In only one saliva sample, and in quite low amounts, arsenic was detected. The results indicate that smoking produces more significant changes in the saliva of women than in men, increasing the concentration of some elements in the saliva of female smokers, much more than in the male smokers. The cigarette usage time also appears to exert a greater influence on the composition of the saliva of women than in men, indicating that the damage caused by cigarette use may in fact be higher in women than in men.

Alternatives to overcoming bacterial resistances: State-of-the-art.

Worldwide, bacterial resistance to chemical antibiotics has reached such a high level that endangers public health. Presently, the adoption of alternative strategies that promote the elimination of resistant microbial strains from the environment is of utmost importance. This review discusses and analyses several (potential) alternative strategies to current chemical antibiotics. Bacteriophage (or phage) therapy, although not new, makes use of strictly lytic phage particles as an alternative, or a complement, in the antimicrobial treatment of bacterial infections. It is being rediscovered as a safe method, because these biological entities devoid of any metabolic machinery do not possess any affinity whatsoever to eukaryotic cells. Lysin therapy is also recognized as an innovative antimicrobial therapeutic option, since the topical administration of preparations containing purified recombinant lysins with amounts in the order of nanograms, in infections caused by Gram-positive bacteria, demonstrated a high therapeutic potential by causing immediate lysis of the target bacterial cells. Additionally, this therapy exhibits the potential to act synergistically when combined with certain chemical antibiotics already available on the market. Another potential alternative antimicrobial therapy is based on the use of antimicrobial peptides (AMPs), amphiphilic polypeptides that cause disruption of the bacterial membrane and can be used in the treatment of bacterial, fungal and viral infections, in the prevention of biofilm formation, and as antitumoral agents. Interestingly, bacteriocins are a common strategy of bacterial defense against other bacterial agents, eliminating the potential opponents of the former and increasing the number of available nutrients in the environment for their own growth. They can be applied in the food industry as biopreservatives and as probiotics, and also in fighting multi-resistant bacterial strains. The use of antibacterial antibodies promises to be extremely safe and effective. Additionally, vaccination emerges as one of the most promising preventive strategies. All these will be tackled in detail in this review paper.

Scaffolds and tissue regeneration: An overview of the functional properties of selected organic tissues.

Tissue engineering plays a significant role both in the re-establishment of functions and regeneration of organic tissues. Success in manufacturing projects for biological scaffolds, for the purpose of tissue regeneration, is conditioned by the selection of parameters such as the biomaterial, the device architecture, and the specificities of the cells making up the organic tissue to create, in vivo, a microenvironment that preserves and further enhances the proliferation of a specific cell phenotype. To support this approach, we have screened scientific publications that show biomedical applications of scaffolds, biomechanical, morphological, biochemical, and hemodynamic characteristics of the target organic tissues, and the possible interactions between different cell matrices and biological scaffolds. This review article provides an overview on the biomedical application of scaffolds and on the characteristics of the (bio)materials commonly used for manufacturing these biological devices used in tissue engineering, taking into consideration the cellular specificity of the target tissue. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1483-1494, 2016.

Development and characterization of a hydrogel containing silver sulfadiazine for antimicrobial topical applications.

Development and optimization of a hydrogel with impregnated silver sulfadiazine was pursued, for antimicrobial topical applications. The selected hydrogel exhibited a homogeneous appearance, with whitish colloration and devoid of any fractures or cracks. The content in impregnated silver sulfadiazine was within established limits (1%, w/w) with a standard deviation of up to 1.28%. The hydrogel presented a good characteristic in relation to release of the active antimicrobial principle, verified through swelling tests and antimicrobial activity. The swelling tests indicated a higher increase in weight during the first 6 h of contact with a moist environment, with a maximum value of 266.00 ± 0.81, and with maintenance of the original shape of the hydrogel. The impregnated silver sulfadiazine presented antimicrobial activity, as expected, indicating a prolonged release of the drug. The infrared spectra of the hydrogel with impregnated silver sulfadiazine indicated that the drug did not engage in any bonds with the polymeric matrix, which otherwise could have reduced its antimicrobial activity. The mechanical resistance tests produced good results, indicating that the hydrogels may be utilized in different locations of the human body with skin lesions.