Nanobiomaterials: a review of the existing science and technology, and new approaches

Nanotechnology has made great strides forward in the creation of new surfaces, new materials and new forms which also find application in the biomedical field. Traditional biomedical applications started benefiting from the use nanotechnology in an array of areas, such as biosensors, tissue engineering, controlled release systems, intelligent systems and nanocomposites used in implant design. In this manuscript a review of developments in these areas will be provided along with some applications from our laboratories.

Advancing tissue engineering by using electrospun nanofibers

Electrospinning is a versatile technique that enables the development of nanofiber-based scaffolds, from a variety of polymers that may have drug-release properties. Using nanofibers, it is now possible to produce biomimetic scaffolds that can mimic the extracellular matrix for tissue engineering. Interestingly, nanofibers can guide cell growth along their direction. Combining factors like fiber diameter, alignment and chemicals offers new ways to control tissue engineering. In vivo evaluation of nanomats included their degradation, tissue reactions and engineering of specific tissues. New advances made in electrospinning, especially in drug delivery, support the massive potential of these nanobiomaterials. Nevertheless, there is already at least one product based on electrospun nanofibers with drug-release properties in a Phase III clinical trial, for wound dressing. Hopefully, clinical applications in tissue engineering will follow to enhance the success of regenerative therapies.

Biodegradable nanomats produced by electrospinning: expanding multifunctionality and potential for tissue engineering

With increasing interest in nanotechnology, development of nanofibers (n-fibers) by using the technique of electrospinning is gaining new momentum. Among important potential applications of n-fiber-based structures, scaffolds for tissue-engineering represent an advancing front. Nanoscaffolds (n-scaffolds) are closer to natural extracellular matrix (ECM) and its nanoscale fibrous structure. Although the technique of electrospinning is relatively old, various improvements have been made in the last decades to explore the spinning of submicron fibers from biodegradable polymers and to develop also multifunctional drug-releasing and bioactive scaffolds. Various factors can affect the properties of resulting nanostructures that can be classified into three main categories, namely: (1) Substrate related, (2) Apparatus related, and (3) Environment related factors. Developed n-scaffolds were tested for their cytocompatibility using different cell models and were seeded with cells for to develop tissue engineering constructs. Most importantly, studies have looked at the potential of using n-scaffolds for the development of blood vessels. There is a large area ahead for further applications and development of the field. For instance, multifunctional scaffolds that can be used as controlled delivery system do have a potential and have yet to be investigated for engineering of various tissues. So far, in vivo data on n-scaffolds are scarce, but in future reports are expected to emerge. With the convergence of the fields of nanotechnology, drug release and tissue engineering, new solutions could be found for the current limitations of tissue engineering scaffolds, which may enhance their functionality upon in vivo implantation. In this paper electrospinning process, factors affecting it, used polymers, developed n-scaffolds and their characterization are reviewed with focus on application in tissue engineering.

Electrospun multifunctional diclofenac sodium releasing nanoscaffold

Electrospinning is a method utilized to produce nano-scale fibers for tissue engineering applications. A variety of cells are attracted by nano scale surfaces and structures probably due to the similarity of their natural environment scale. In this study, diclofenac sodium (DS) releasing nanofibers were manufactured via electrospinning process. Poly(95 epsilon-capro/5 D,L-lactide) was dissolved into acetic acid to form a 20% w/v solution. 2% w/w of DS was then added into the polymer solution and stirred homogenously. About 1 g of polymer/drug solution was spun onto the collector under electrostatic conditions. The distance between needle tip and sample collector was arranged to 10 cm and applied electric field was 2 kV/cm. Release rate of DS was measured by using UV/VIS spectrophotometer. Resulted highly porous nanofiber scaffold was about 2 mm thick and the diameter of nanofibers was approximately 130 nm. Structure included in also spheres with approximately diameter of 3.30 microm. About 45% of DS was released during the first 24 hours and after that the release decreased to almost zero value. After 35 days release rate increased. This study revealed that manufacturing of highly porous DS releasing nanoscaffold by electrospinning process is feasible. Having fast DS release rate nanofibrous scaffold made of poly(95 epsilon-capro/5 D,L-lactide) can be of benefit for applications where immediate control of tissue reaction is needed.

Biodegradable nanomats produced by electrospinning: expanding multifunctionality and potential for tissue engineering

With increasing interest in nanotechnology, development of nanofibers (n-fibers) by using the technique of electrospinning is gaining new momentum. Among important potential applications of n-fiber-based structures, scaffolds for tissue-engineering represent an advancing front. Nanoscaffolds (n-scaffolds) are closer to natural extracellular matrix (ECM) and its nanoscale fibrous structure. Although the technique of electrospinning is relatively old, various improvements have been made in the last decades to explore the spinning of submicron fibers from biodegradable polymers and to develop also multifunctional drug-releasing and bioactive scaffolds. Various factors can affect the properties of resulting nanostructures that can be classified into three main categories, namely: (1) Substrate related, (2) Apparatus related, and (3) Environment related factors. Developed n-scaffolds were tested for their cytocompatibility using different cell models and were seeded with cells for to develop tissue engineering constructs. Most importantly, studies have looked at the potential of using n-scaffolds for the development of blood vessels. There is a large area ahead for further applications and development of the field. For instance, multifunctional scaffolds that can be used as controlled delivery system do have a potential and have yet to be investigated for engineering of various tissues. So far, in vivo data on n-scaffolds are scarce, but in future reports are expected to emerge. With the convergence of the fields of nanotechnology, drug release and tissue engineering, new solutions could be found for the current limitations of tissue engineering scaffolds, which may enhance their functionality upon in vivo implantation. In this paper electrospinning process, factors affecting it, used polymers, developed n-scaffolds and their characterization are reviewed with focus on application in tissue engineering.