Natural rubber latex from the
Hevea brasiliensis
has been of great importance in areas such as medicine and bioengineering, due to its angiogenic and wound healing activity. However, the ...biodegradability of natural rubber latex is not significant when compared to other polymers used for the development of materials with biomedical applications, which is important to avoid medical intervention to remove them. Thus, the aim of this work was to improve the biodegradability and subsequent bioabsorption of natural rubber latex membranes associating them with the polylactic acid, a biodegradable, bioreabsorbable and biocompatible polymer, besides being the most studied in biomedical, pharmaceutical and environmental fields. The membranes were prepared with different mass proportions of the polymers with dichloromethane as solvent. The material were submitted to mechanical test, infrared spectroscopy, scanning electron microscopy, water vapor transmission, swelling, in vitro degradation and hemolysis assay. The different polymer proportions influenced the membrane properties. The infrared spectroscopy indicating that no new chemical interactions were formed, and the scanning electron microscopy showed a polymer network formed in membranes with the highest natural rubber latex mass proportion. With the increase of polylactic acid in the membranes, there was an improvement in the degradation of the material of up to 130% and no hemolytic effect was observed, making it interesting for biomedical application.
Skin wound infection requires carefully long-term treatment with an immense financial burden to healthcare systems worldwide. Various strategies such as drug delivery systems using polymer matrix ...from natural source have been used to enhance wound healing. Natural rubber latex (NRL) from Hevea brasiliensis has shown angiogenic and tissue repair properties. Gentamicin sulfate (GS) is a broad-spectrum antibiotic which inhibits the growth of a wide variety of microorganisms and, because of this, it has also been applied topically for treatment of local infections. The aim of this study was to develop a GS release system using NRL as matrix for Staphylococcus aureus and Escherichia coli infected skin ulcers treatment, without changing drug antibiotic properties. The matrix did not change the GS antimicrobial activity against S. aureus and E. coli strains. Moreover, the NRL-GS biomembrane did not exhibit hemolytic activity, being non-toxic to red blood cells. The eluates of NRL-GS biomembranes and GS solutions did not significantly reduce the survival of Caenorhabditis elegans worms for 24 h at any of the tested concentrations. Thus, these results emphasize that the NRL-GS biomembrane proved to be a promising biomaterial for future studies on the development of dressings for topical uses, inexpensive and practicable, keeping drug antibiotic properties against pathogens and to reduce the side effects.
Natural rubber latex (NRL) is a natural polymer which has arisen large interest in the biomedical field, mostly, due to its ability to facilitate angiogenesis and therefore, tissue repair. ...Moxifloxacin (MXF) is a broad-spectrum antibiotic orally administrated. Considering the biological properties of the NRL and its ability to deliver a wide range of compounds, the present study aimed to develop a novel device for infected chronic wound treatment. MXF-loaded NRL was obtained by a casting method. The results demonstrated that the incorporation of MXF in NRL did not promote any molecular interaction, preserving the integrity of the compounds. The mechanical properties of the biomaterial did not show any significant change, indicating enough elasticity for dermal application. The microbiological assays confirmed the ability of the polymer to deliver the drug without influencing its pharmacological properties. Moreover, it has expressed activity against major bacterial strains presented in wound infections. Finally, the biomaterial shown biocompatibility from the in vitro study. Thus, the present work has shown that MXF-loaded NRL membrane is a promising biomaterial to infected wound treatment.
This work aimed to produce a membrane based on fluconazole-loaded natural rubber latex (NRL), and study their interaction, drug release and antifungal susceptibility against Candida albicans.
...Fluconazole-loaded NRL membrane was obtained by casting method.
The Fourier Transform Infrared Spectroscopy showed no modifications either in NRL or fluconazole after the incorporation. Mechanical test presented low Young's modulus and high strain, indicating the membranes have sufficient elasticity for biomedical application. The bio-membrane was able to release the drug and inhibit the growth of C. albicans as demonstrated by disk diffusion and macrodilution assays.
The biomembrane was able to release fluconazole and inhibit the growth of C. albicans, representing a promising biomaterial for skin application.
Background
Nipple pain is the second most common reason for early weaning, exceeded only by the insufficient milk supply. Nipple fissures can bring other problems, acting also as a portal for ...bacteria and leading to mastitis. This work proposes the breast protector composite development using materials with tissue repair and moisturizing properties, aligned with a low‐cost procedure, aiming not only to relieve pain, but also to heal the nipple fissures caused by breastfeeding.
Materials and methods
For the dressings, production was used Natural Latex extracted from the rubber tree and glycerol. The Samples were evaluated chemically and physically by the techniques of Scanning Electron Microscopy, Fourier transform infrared spectroscopy, mechanical traction, and contact angle. The samples were also biologically evaluated by the hemolytic and cytotoxic activity assays.
Results
From the physical‐chemical assays, the matrix with glycerol has high pore density; the natural latex and glycerol do not covalently interact, indicating that the glycerol can be released; the glycerol addition makes the matrix more elastic but fragile, and increase the wettability. From the biological assays, both materials showed no hemolytic effects; and the cytotoxicity results showed that glycerol did not present cytotoxicity in the fibroblasts, but show a dose‐dependent influence in the keratinocytes.
Conclusion
The material developed for application in breast fissures has mechanical properties similar to those found for materials for dermal applications, present high wettability and pore density. Furthermore, the material showed no cytolytic activity and the tests with skin cell cultures demonstrated the biocompatibility.
The most used approach in the motor rehabilitation of spinal cord injury is functional electrical stimulation. However, current devices do not provide real-time feedback, work in the closed-loop, and ...became remotely operable. In this scenario, this paper presents the development of an open access 4-channel IoT electrostimulator device with an inertial sensor. The electrostimulator circuit was designed with four modules: Boost Converter, H-bridge, Inertial Measurement Unit, and Processing Module. The firmware was implemented in the processing module to manage the modules to perform closed-loop stimulation (using PID controller). To perform the proof of concept of the device, a closed loop test was performed to control the ankle joint, performing the movements of dorsiflexion, plantar flexion, inversion, and eversion. The designed hardware allowed one to freely change the boost converter voltage and modulate the signal with 200 μs of pulse duration and 50 Hz of period in a safe and stable way. Furthermore, the controller was able to move the ankle joint in all desired directions following the reference values and respecting the imposed constraints. In general, the developed hardware was able to safely control a closed-loop joint.
Background
Mesenchymal stem cells (MSCs) are undifferentiated cells and can be isolated from many tissues, including adipose tissue. MSCs neuronal differentiation ability has arisen interest in ...research with these cells in neurodegenerative diseases, such as Parkinson’s disease (PD). To differentiate MSCs in cells that produce dopamine that posteriorly potential to be a safe cell therapy for PD.
Methods
MSCs were isolated from adipose tissue, characterized by flow cytometry and trilineage differentiation, and cultivated seeded on natural functional biopolymer matrix (NFBX) to differentiate in neuronal precursors. Finally, a neural precursor was cultivated in the dopaminergic differentiation medium. The immunocytochemistry was performed with antibody anti-Nestin for precursor neural and antibodies anti-ß III-tubulin and hydroxylase tyrosine. Then, quantification of dopamine was made by the ELISA kit in the culture medium.
Results
The cytometric analysis of MSCs and the trilineage test to chondrocyte, osteocyte, and adipocyte demonstrated their pluripotency. Cells seeded and cultivated over NFBX have developed neurospheres, and their mechanical dissociated cells were Nestin positive. Dopaminergic differentiation was confirmed with positivity for ß-III tubulin and hydroxylase tyrosine. The dopamine concentration was very high in one sample (74.91 ng/mL). Without this sample, the media was 2.34 ± 2.13 ng/mL. The difference between dopamine concentrations was probably due to donors' metabolic characteristics.
Conclusions
The MSCs differentiated in neural precursor cells without genetic modification or growth factors, using only this NFBX. When these neural precursors were induced to differentiate, they were available to produce dopamine, demonstrating a functional neuronal differentiation.
Ketoprofen is an analgesic with potent anti-inflammatory activity against acute inflammation, subacute inflammation, for the acute and long-term treatment of various inflammatory pathologies, as ...rheumatoid arthritis and colonic adenocarcinoma. In order to minimize the incidence of systemic events related to ketoprofen, the transdermal drug delivery system development has been most important. The advantages of using natural rubber latex membranes include not only the reduction of adverse systemic events, but also the suitability of the low cost of the material together with its physicochemical properties such as flexibility, mechanical stability, surface porosity and water vapor permeability, and besides being a biocompatible material also presents biological activity to stimulate the angiogenesis, being able to be used in tissue repair. This study demonstrated that ketoprofen was successfully incorporated into natural latex membranes for drug delivery. FTIR indicated that the drug did not interact chemically with the membrane. Moreover, the natural latex membranes released 60% of the ketoprofen incorporated in 50 h. SEM images indicated that a portion of the drug was present on the membrane surface, being this portion responsible for the burst release. The tensile tests showed that the addition of the drug into the natural latex membrane did not influence on the polymer mechanical behavior. In addition, drug-natural latex membranes presented no red blood cell damaging effects. Our data shows that the ketoprofen loaded natural latex membranes is a promising system for sustained drug delivery which can be used to minimize the adverse side effects of high dose systemic drug delivery.
Neurogenic bladder is a dysfunction in the lower urinary tract due to damage to the nervous system. One of the treatments that has shown important results is transcutaneous neuromodulation. The ...neuromodulation equipment available on the market does not allow remote activation or offer many resources for adjusting the parameters of the generated stimulus, as most devices operate with pre-established parameters in closed packages. For this reason, customizing therapy for each individual can be difficult. Therefore, the objective was to develop and validate a neuromodulation device capable of being remotely programmed and properly monitored. Materials and methods for validating devices were used according to the Brazilian Regulatory Standard (NBR), which deals with general requirements for the basic safety and essential performance of electromedical devices. After verifying the reliability of the device, which was capable of generating a biphasic and symmetrical wave, measured by an oscilloscope, considered safe by the technical requirements, it was tested in a real application. Users reported feeling a comfortable stimulus, similar to other previously used devices, and considered the device easy to use. In this way, it was possible to demonstrate the reliability and validity of the developed device.
The incorporation of drugs and bioactive compounds in the natural rubber latex (NRL) matrix has been an alternative for the development of transdermal release membranes. Ibuprofen (IBF) is known to ...be used to treat inflammatory diseases, but when administered orally, high concentrations can cause some adverse problems. In this work, the incorporation of IBF in the NRL membranes was evaluated by physical-chemical, in vitro permeation, hemocompatibility and molecular modeling assays. In addition, the in vitro release profile of IBF in acid and basic media was analyzed during 96 h. The IBF-NRL membrane exhibited the absence of intermolecular bonding that could hinder drug release and presented compatible mechanical properties for applications as a cutaneous adhesive (0.58 and 1.12 MPa to Young’s modulus and rupture tension, respectively). The IBF-NRL system did not present a significant hemolysis degree (1.67%) within 24 h. The release test indicated that in the first hours of the study, 48.5% IBF was released at basic pH and 22.5% at acidic pH, which is characteristic of a burst effect. Then, a stable release profile was observed until the end of the assay, with total IBF release of 60% in alkaline medium and 50% in acidic medium. The drug permeation results indicated that the IBF-NRL membranes can be used for the local skin treatment with permeation of 3.11% of IBF. Dynamic Molecular simulations indicated a pronounced electric dipole in the ionized form of IBF, which suggests a more effective interaction with water, explaining the efficient drug release in alkaline solutions. In general, the results demonstrate that the IBF-NRL membrane has great potential for a new adhesive that can be used for the treatment of inflammatory processes and injuries.
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