Ciprofloxacin release using natural rubber latex membranes as carrier

Natural rubber latex-based biomaterials for drug delivery and regenerative medicine: Trends and directions

Natural Rubber Latex (NRL) has shown to be a promising biomaterial for use as a drug delivery system to release various bioactive compounds. It is cost-effective, easy to handle, biocompatible, and exhibits pro-angiogenic and pro-healing properties for both soft and hard tissues. NRL releases compounds following burst and sustained release kinetics, exhibiting first-order release kinetics. Moreover, its pore density can be adjusted for tailored kinetics profiles. In addition, biotechnological applications of NRL in amblyopia, smart mattresses, and neovaginoplasty have demonstrated success. This comprehensive review explores NRL's diverse applications in biotechnology and biomedicine, addressing challenges in translating research into clinical practice. Organized into eight sections, the review emphasizes NRL's potential in wound healing, drug delivery, and metallic nanoparticle synthesis. It also addresses the challenges in enhancing NRL's physical properties and discusses its interactions with the human immune system. Furthermore, examines NRL's potential in creating wearable medical devices and biosensors for neurological disorders. To fully explore NRL's potential in addressing important medical conditions, we emphasize throughout this review the importance of interdisciplinary research and collaboration. In conclusion, this review advances our understanding of NRL's role in biomedical and biotechnological applications, offering insights into its diverse applications and promising opportunities for future development.

Porous Deproteinized Natural Rubber Film Loaded with Silver Nanoparticles for Topical Drug Delivery

The work demonstrated the use of natural rubber for topical drug delivery. The first objective was to fabricate a porous deproteinized natural rubber film loaded with silver nanoparticles. Characterizing and assessing its formulation was the second objective. Surface pH, mechanical properties, swelling ratio, erosion, moisture vapor transmission rate, scanning electron microscopy/energy dispersive X-ray analysis, and X-ray diffraction were evaluated. In vitro studies and antibacterial activity were assessed. It was discovered that silver nanoparticles could enter the film and that their concentrations ranged between 7.25 and 21.03 µg/cm2. The pH of the film's surface was 7.00. The mechanical properties of the film with silver nanoparticle loading differed from the blank film. After adding silver nanoparticles, the film eroded faster than before, but the swelling ratio was not affected significantly. Increased time utilization had an impact on the moisture vapor transmission rate of the film. Silver nanoparticles released easily from the film while there was less permeability. The dead pig-ear skin had significant silver nanoparticle accumulation. Potent antibacterial activity was seen in the film containing silver nanoparticles. The silver nanoparticle-loaded film may be used as a wound dressing for a topical film that promotes wound healing while also protecting the area from infection.

Biocompatible anti-aging face mask prepared with curcumin and natural rubber with antioxidant properties

Natural rubber latex (NRL) is a biopolymer widely used in biomedical applications. In this work, we propose an innovative cosmetic face mask, combining the NRL's biological properties with curcumin (CURC), which has a high level of antioxidant activity (AA) to provide anti-aging benefits. Chemical, mechanical and morphological characterizations were performed. The CURC released by the NRL was evaluated by permeation in Franz cells. Cytotoxicity and hemolytic activity assays were performed to assess safety. The findings showed that the biological properties of CURC were preserved after loading in the NRL. About 44.2 % of CURC was released within the first six hours, and in vitro permeation showed that 9.36 % ± 0.65 was permeated over 24h. CURC-NRL was associated with a metabolic activity higher than 70 % in 3 T3 fibroblasts, cell viability ≥95 % in human dermal fibroblasts, and a hemolytic rate ≤ 2.24 % after 24 h. Furthermore, CURC-NRL maintained the mechanical characteristics (range suitable) for human skin application. We observed that CURC-NRL preserved ~20 % antioxidant activity from curcumin-free after loading in the NRL. Our results suggest that CURC-NRL has the potential to be used in the cosmetics industry, and the experimental methodology utilized in this study can be applied to different kinds of face masks.

Glycerol and Antimicrobial Peptide-Modified Natural Latex for Bacteriostasis of Skin Wounds

This work aimed to develop a glycerol antimicrobial peptide natural latex film (NRL-GI-AMP film) for the treatment of skin wound infections. The contents of this work mainly include investigating the effect of adding glycerol (GI) and an antimicrobial peptide (AMP) on the physical and chemical properties of natural latex (NRL) and analyzing the cytocompatibility, bacteriostatic activity, and infected wound healing promotion of the NRL-GI-AMP film. The results showed that the addition of GI resulted in more pores in the internal structure of the NRL film, while the addition of G(LLKK)₃L AMP did not change the structure and properties of the NRL film. Compared with that of the NRL film, the infrared spectrum of the NRL-GI-AMP film did not produce new characteristic peaks, indicating that GI and AMP were non-covalently cross-linked with NRL. Addition of 10% GI reduces the toughness of the NRL-GI-AMP film by 62.0%, increases the water vapor transmission rate by 8.95 mg/(cm²·h), and reduces the water absorption and water retention distributions by 33.0 and 24.7%, respectively. AMP in the NRL-GI-AMP film could be released continuously for 40 h, and the release rate was about 45%. The NRL-GI-AMP film showed good biocompatibility and antibacterial activity and promoted the healing of infected wounds. Therefore, the NRL-GI-AP film has potential application in the development of dressings to inhibit skin wound infection and promote wound healing.

Drug-Eluting Rubber Bands for Tissue Ligation

Rubber band ligation is a commonly used method for the removal of tissue abnormalities. Most often, rubber band ligation is performed to remove internal hemorrhoids unresponsive to first line treatments to avoid surgery. While the procedure is considered safe, patients experience mild to significant pain and discomfort until the tissue sloughs off. As patients often require multiple bandings and sessions, reducing these side effects can have a considerable effect on patient adherence and quality of life. To reduce pain and discomfort, we developed drug-eluting rubber bands for ligation procedures. We investigated the potential for a band to elute anesthetics and drug combinations to durably manage pain for a period of up to 5 days while exhibiting similar mechanical properties to conventional rubber bands. We show that the rubber bands retain their mechanical properties despite significant drug loading. Lidocaine, released from the bands, successfully altered the calcium dynamics of cardiomyocytes in vitro and modulated heart rate in zebrafish embryos, while the bands exhibited lower cytotoxicity than conventional bands. Ex vivo studies demonstrated substantial local drug release in enteric tissues. These latex-free bands exhibited sufficient mechanical and drug-eluting properties to serve both ligation and local analgesic functions, potentially enabling pain reduction for multiple indications.

Natural rubber dressing loaded with silver sulfadiazine for the treatment of burn wounds infected with Candida spp

Millions of people are burned worldwide every year and 265,000 of the cases are fatal. The development of burn treatment cannot consist only of the administration of a single drug. Due to the infection risk, antibiotics are used in conjunction with gels and damp bandages. In this work, an inexpensive curative based on silver sulfadiazine (SS) and natural rubber latex (NRL) was developed to treat burn wounds. It was produced by the casting method. The infrared spectrum presented no interaction between drug and biopolymer. At the same time, electronic micrographs showed that the SS crystals are inserted on the polymeric dressing surface. Mechanical properties after the drug incorporation were considered suitable for dermal application. About 32.4% of loaded SS was released in 192 h by the dressings that also inhibited the growth of Candida albicans and Candida parapsilosis at 75.0 and 37.5 μg·mL^-1, respectively. The curative proved to be biocompatible when applied to fibroblast cells, in addition to enhancing cellular proliferation and, in the hemocompatibility test, no hemolytic effects were observed. The good results in mechanical, antifungal and biological assays, combined with the average bandage cost of $0.10, represent an exciting alternative for treating burn wounds.

Biomedical applications of natural rubber latex from the rubber tree Hevea brasiliensis

The past decades have witnessed tremendous progress in biomaterials in terms of functionalities and applications. To realize various functions such as tissue engineering, tissue repair, and controlled release of therapeutics, a biocompatible and biologically active material is often needed. However, it is a difficult task to find either synthetic or natural materials suitable for in vivo applications. Nature has provided us with the natural rubber latex from the rubber tree Hevea brasiliensis, a natural polymer that is biocompatible and has been proved as inducing tissue repair by enhancing the vasculogenesis process, guiding and recruiting cells responsible for osteogenesis, and acting as a solid matrix for controlled drug release. It would be extremely useful if medical devices can be fabricated with materials that have these biological properties. Recently, various types of natural rubber latex-based biomedical devices have been developed to enhance tissue repair by taking advantage of its biological properties. Most of them were used to enhance tissue repair in chronic wounds and critical bone defects. Others were used to design drug release systems to locally release therapeutics in a sustained and controlled manner. Here, we summarize recent progress made in these areas. Specifically, we compare various applications and their performance metrics. We also discuss critical problems with the use of natural rubber latex in biomedical applications and highlight future opportunities for biomedical devices produced either with pre-treated natural rubber latex or with proteins purified from the natural rubber latex.

Gentamicin encapsulated within a biopolymer for the treatment of Staphylococcus aureus and Escherichia coli infected skin ulcers

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.

Antifungal activity of fluconazole-loaded natural rubber latex against Candida albicans

Aim: 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. Materials & methods: Fluconazole-loaded NRL membrane was obtained by casting method. Results: 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. Conclusion: The biomembrane was able to release fluconazole and inhibit the growth of C. albicans, representing a promising biomaterial for skin application.

Recycle of Immobilized Endocellulases in Different Conditions for Cellulose Hydrolysis

The immobilization of cellulases could be an economical alternative for cost reduction of enzyme application. The derivatives obtained in the immobilization derivatives were evaluated in recycles of paper filter hydrolysis. The immobilization process showed that the enzyme recycles were influenced by the shape (drop or sheet) and type of the mixture. The enzyme was recycled 28 times for sheets E' and 13 times for drops B'. The derivative E' showed the highest stability in the recycle obtaining 0.05 FPU/g, RA of 10%, and FPU Yield of 1.64 times, higher than FPU spent or Net FPU Yield of 5.3 times, saving more active enzymes. The derivative B showed stability in recycles reaching 0.15 FPU/g of derivative, yield of Recovered Activity (RA) of 25%, and FPU Yield of 1.57 times, higher than FPU spent on immobilization or Net PFU Yield of 2.81 times. The latex increased stability and resistance of the drops but did not improve the FPU/gram of derivative.

Sericin-binded-deprotenized natural rubber film containing chitin whiskers as elasto-gel dressing

Here, we aims to demonstrate a simple concept in biomaterials design by using natural resources solely as raw materials to fabricate elastic wound care dressing. Elasto-gel films comprise of silk sericin (SRC), natural rubber (NR), and chitin whisker (CTW) were developed. A glue-like protein SRC found in silk cocoons is beneficial for the treatment of wounds due to its superior skin moisturizing ability. However, the pure SRC film is generally difficult to be fabricated because of its weak structural feature. This limitation was overcome by using NR as a binder which consecutively rendered elasticity and strength of the films. CTW was chosen as another component to promote ability of the films for tissue restoration. Before the film formation, protein in the natural rubber latex (NRL) was removed to avoid allergic and cytotoxic problems. The enzyme-treated NR/SRC (ETNR/SRC) films having different blend compositions were fabricated by solution casting technique. The highest amount of the SRC to gain an easy to handle ETNR/SRC film was 30%. The ETNR/SRC/CTW films having 20% SRC were fabricated and studied in comparison. Essential properties of the films as elastic wound care dressings were investigated and effect of the materials chemistry on the observed properties were discussed.

pH-Responsive 2-hydroxyethyl methacrylate/citraconic anhydride–modified collagen hydrogels as ciprofloxacin carriers for wound dressings

pH-Sensitive hydrogels of 2-hydroxyethyl methacrylate/citraconic anhydride–modified collagen were obtained by free radical copolymerization/crosslinking in the presence of ammonium persulfate/ N,N,N′, N′-tetramethylethylenediamine redox initiator system. Their pH-responsiveness was demonstrated by swelling behavior and ciprofloxacin release tests. Both unloaded and loaded hydrogels were characterized by Fourier transform infrared, scanning electron microscopy, and biocompatibility tests. The enzymatic degradation in the presence of Clostridium histolyticum mainly depends on initiator content. In vivo biocompatibility tests involving intraperitoneal hydrogels’ implantation in rats following the analysis by the granuloma test, leukocyte formula, immune parameters, and hepatic transaminases demonstrated their non-toxicity and biocompatibility with living tissues. The in vitro antimicrobial activity, in vivo biocompatibility, and in vitro biodegradability tests attest the possibility to use these new polymeric hydrogels with tailored properties as matrices for bioactive products in medical and pharmaceutical applications as wound care and targeting drug delivery systems. The ciprofloxacin release studies proved their potential as materials for wound dressings.

Diclofenac Potassium Transdermal Patches Using Natural Rubber Latex Biomembranes as Carrier

The aim of this study was to design a compound transdermal patch containing diclofenac potassium (Dic-K) using natural rubber latex (NRL) biomembrane. The NRL from Hevea brasiliensis is easily manipulated and low cost and presents high mechanical resistance. It is a biocompatible material which can stimulate natural angiogenesis and is capable of adhering cells on its surface. Recent researches have used the NRL for Transdermal Drug Delivery Systems (TDDSs). Dic-K is used for the treatment of rheumatoid arthritis and osteoarthritis and pain relief for postoperative and posttraumatic cases, as well as inflammation and edema. Results showed that the biomembrane can release Dic-K for up to 216 hours. The kinetics of the Dic-K release could be fitted with double exponential function. X-ray diffraction and Fourier Transform Infrared (FTIR) spectroscopy show some interaction by hydrogen bound. The results indicated the potential of the compound patch.