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Meital Zilberman – 1st expert on this subject based on the ideXlab platform
Fiber‐reinforced composite hydrogels for bioadhesive and sealant applicationsPolymers for Advanced Technologies, 2017Co-Authors: Oded Pinkas, Or Haneman, Omer Chemke, Meital ZilbermanAbstract:
The use of Bioadhesives and sealants for wound closure and healing applications is becoming more and more popular, particularly when other techniques, such as stapling or suturing, are impractical or inefficient. Loading adhesives with fibers has tremendous potential for improving their mechanical properties. The concept of fiber-reinforced Bioadhesives and sealants is novel and has not been investigated to date. In the present study, natural cellulose fibers were selected for enhancement of bioadhesive properties. A bioadhesive formulation based on a combination of gelatin and alginate crosslinked with water-soluble carbodiimide was used as a generic formulation for this study, on the basis of our previous studies. The polymeric matrix and the cellulose fibers showed high affinity, which resulted in a dramatic increase in the viscosity and in the burst strength. They moderately affected the curing time, swelling, and weight loss. A mixed response was found in the compression modulus and the bonding strength in lap shear. We demonstrated that fiber-reinforced Bioadhesives have a great potential for surgical sealant applications because of improvement in the cohesive strength of the composite hydrogel. This study presents proof of the concept of using fibers for the enhancement of bioadhesive properties as a result of fiber-reinforcement and may comprise the basis for future studies in this field. Copyright © 2017 John Wiley & Sons, Ltd.
structuring of composite hydrogel Bioadhesives and its effect on properties and bonding mechanismActa Biomaterialia, 2017Co-Authors: Oded Pinkas, Daniella Goder, Roni Noyvirt, Sivan Peleg, Maayan Kahlon, Meital ZilbermanAbstract:
Abstract Bioadhesives are polymeric hydrogels that can adhere to a tissue after crosslinking and are an essential element in nearly all surgeries worldwide. Several Bioadhesives are commercially available. However, none of them are ideal. The main limitation of current tissue adhesives is the tradeoff between biocompatibility and mechanical strength, especially in wet hemorrhagic environments. Our novel Bioadhesives are based on the natural polymers gelatin (coldwater fish) and alginate, crosslinked by carbodiimide (EDC). Two types of hemostatic agents with a layered silicate structure, montmorillonite (MMT) and kaolin, were loaded in order to improve the sealing ability in a hemorrhagic environment. The effect of the adhesive’s components on its mechanical strength was studied by three different methods – burst strength, lap shear and compression. The viscosity, gelation time and structural features of the adhesive were also studied. A qualitative model that describes the effect of the bioadhesive’s parameters on the cohesive and adhesive strength was developed. A formulation based on 400 mg/mL gelatin, 10 mg/mL alginate and 20 mg/mL EDC was found as optimal, enabling a burst strength of 387 mmHg. Incorporation of kaolin increased the burst strength by 25% due to microcomposite structuring, whereas MMT increased the burst strength by 50% although loaded in a smaller concentration, due to nano-structuring effects. This research clearly shows that the incorporation of kaolin and MMT in gelatin-alginate surgical sealants is a very promising novel approach for improving the bonding strength and physical properties of surgical sealants for use in hemorrhagic environments. Statement of Significance The current manuscript focuses on novel Bioadhesives, based on natural polymers and loaded with hemostatic agents with a layered silicate structure, in order to improve the sealing ability in hemorrhagic environment. Such composite Bioadhesives have not been developed and studied before. The effect of the adhesive’s components on its mechanical strength was studied by three different methods, as well as the physical properties and structural features. Thorough understanding of these unique biomaterials resulted in a qualitative model which describes the effect of the bioadhesive’s parameters on the cohesive and adhesive strength. Thus, structure-property-function relationships are presented. Structuring of the composite Bioadhesives and its effect of the properties and bonding mechanism, are expected to be of high interest to Acta readership.
effect of gamma radiation on novel gelatin alginate based BioadhesivesInternational Journal of Polymeric Materials, 2016Co-Authors: Maytal Foox, M Bentzur, N Koifman, Meital ZilbermanAbstract:
ABSTRACTTissue Bioadhesives are gaining popularity as an alternative for sutures and staples. The authors have previously developed novel Bioadhesives based on gelatin and alginate, crosslinked with carbodiimide. However, the Bioadhesives must be sterilized before proceeding to clinical trials. The effect of gamma irradiation, a common sterilization method, was investigated in the current study. The viscosity was significantly decreased, while the bonding strength to the tissue (a) and the gelatin release from the Bioadhesives were not affected significantly due to the exposure to gamma radiation. The results also indicate that a gamma radiation dose of 25 kGy, as is customary for biomedical applications, has a minor effect on human fibroblast viability when using formulations based on low concentration of carbodiimide (b). These results enabled the authors to positively consider gamma irradiation as a sterilization method for their Bioadhesives.
Sanjay Garg – 2nd expert on this subject based on the ideXlab platform
Development and evaluation of a buccal bioadhesive system for smoking cessation therapyPharmazie, 2007Co-Authors: Sanjay Garg, G KumarAbstract:
The objective of the present study was to develop a bilayered buccal bioadhesive film formulation of nicotine hydrogen tartrate for smoking cessation therapy, comprising a bioadhesive drug layer and a backing layer, which releases the drug at a pre-determined rate for a period of 4 h. Formulations were prepared using various bioadhesive polymers and were evaluated for physical parameters like peelability, flexibility, softness, bioadhesive strength, tensile strength, dispersion time and pharmaceutical parameters such as thickness, swelling, content uniformity, water vapour permeability and drug release. Based on these parameters formulation N2, containing hydroxypropyl methylcellulose and polycarbophil as the bioadhesive polymers, was selected as the optimized formulation. The formulation showed suitable adhesion and an initial burst release of 40% drug in first 15 min followed by a total 80% drug release in a characteristic manner until 4 h; which is the desired time of application. This release pattern is beneficial for patients suffering from emergent cravings. Backing layers of the films were studied by a moisture vapor permeability test and it was observed that the percentage of moisture which permeated through single layered films was much higher than through bilayered films implying that a backing layer would prevent washing out of drug by the saliva. (33 refs.)
bioadhesive microspheres as a controlled drug delivery systemInternational Journal of Pharmaceutics, 2003Co-Authors: Jaspreet Kaur Vasir, Kaustubh Tambwekar, Sanjay GargAbstract:
Abstract The concept of controlled drug delivery has been traditionally used to obtain specific release rates or spatial targeting of active ingredients. The phenomenon of bioadhesion, introduced by Park and Robinson [Park, K., Robinson, J.R., 1984. Bioadhesive polymers as platforms for oral controlled drug delivery: method to study bioadhesion. Int. J. Pharm. 198, 107–127], has been studied extensively in the last decade and applied to improve the performance of these drug delivery systems. Recent advances in polymer science and drug carrier technologies have promulgated the development of novel drug carriers such as bioadhesive microspheres that have boosted the use of “bioadhesion” in drug delivery. This article presents the spectrum of potential applications of bioadhesive microspheres in controlled drug delivery ranging from the small molecules, to peptides, and to the macromolecular drugs such as proteins, oligonucleotides and even DNA. The development of mucus or cell-specific bioadhesive polymers and the concepts of cytoadhesion and bioinvasion provide unprecedented opportunities for targeting drugs to specific cells or intracellular compartments. Developments in the techniques for in vitro and in vivo evaluation of bioadhesive microspheres have also been discussed.
Jayanta Haldar – 3rd expert on this subject based on the ideXlab platform
biocompatible injectable hydrogel with potent wound healing and antibacterial propertiesMolecular Pharmaceutics, 2017Co-Authors: Jiaul Hoque, Relekar G Prakash, Krishnamoorthy Paramanandham, Bibek Ranjan Shome, Jayanta HaldarAbstract:
Two component injectable hydrogels that cross-link in situ have been used as noninvasive wound-filling devices, i.e., sealants. These materials carry a variety of functions at the wound sites, such as sealing leaks, ceasing unwanted bleeding, binding tissues together, and assisting in wound healing processes. However, commonly used sealants typically lack antibacterial properties. Since bacterial infection at the wound site is very common, bioadhesive materials with intrinsic antibacterial properties are urgently required. Herein, we report a biocompatible injectable hydrogel with inherent bioadhesive, antibacterial, and hemostatic capabilities suitable for wound sealing applications. The hydrogels were developed in situ from an antibacterial polymer, N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC), and a bioadhesive polymer, polydextran aldehyde. The gels were shown to be active against both Gram-positive and Gram-negative bacteria, including drug-resistant ones such as methicillin-resis…