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About Authors:
Neeraj Kumar Lohani, 2Vachaspati Mishra, 3Divakar Joshi
Department of Biotechnology, Institute of Biomedical Education and Research, Mangalayatan University, Beswan, Aligarh-Uttar Pradesh, india,
MBPG College Haldwani Nainital Kumaun University Nainital Uttarakhand.

The interdisciplinary approach with nanotechnology and animal tissue culture technique is going to revolutionize biomedical science in the next fifty years. Nanotechnology along  with regulated animal tissue culture, makestissue engineering a realization  based on the creation of new tissues in vitro followed by surgical placement in the body or the stimulation of normal repair in situ using bio-artificial constructs or implants of living cells introduced in or near the area of damage at nano level.It makes use of artificially stimulated cell proliferation by using suitable nano-material based scaffolds and growth factors. Nanotechnology can be successfully used to create a tissue or organ that can take the place of one that is terminally diseased, such as an eye, ear, heart, or joint. Implantable prosthetic devices and nano scaffolds are used for growing of artificial organs. The key components of tissue engineering with nanotechnology include: cells, scaffolds, signals and bioreactors. Scaffolds are produced by electro-spinning technique.The scaffold acts as an interim synthetic extra cellular matrix (ECM) that cells interact with prior to forming a new tissue. 

Nano materials such as quantum dots, fluorescent carbon nano tubes and fluorescent magnetic nano particles, etc., are been used for imaging and tracing and for gene or drug delivery. Designed nanostructures have been used to regulate the proliferation and differentiation of stem cells, which will speed up the understanding and controlling the micro environmental signals, helping to solve the current bottleneck problems of tissue -based therapy. In the future, we could imagine a world where medical nano devices are routinely implanted or even injected into the bloodstream to monitor wellness and to automatically participate in the repair of systems that deviate from established norms.


PharmaTutor (ISSN: 2347 - 7881)

Volume 2, Issue 1

Received On: 09/012/2014; Accepted On: 15/12/2014; Published On: 15/01/2014

How to cite this article: NK Lohani, V Mishra, D Joshi, A New Promise: Neural Tissue Engineering using Nanotechnology, PharmaTutor, 2014, 2(1), 13-20

The field of tissue engineering has developed in phases: initially researchers searched for “inert” Biomaterials to act solely as replacement structures in the body (Hoerstrup SP et al., 2004).. Then, they explored biodegradable scaffolds both naturally derived and synthetic for the temporary support of growing tissues. Discoveries in nanotechnology have driven both our understanding of cell–substrate interactions, and our ability to influence them. By operating at the size regime of proteins themselves, nanotechnology gives us the opportunity to directly speak the language of cells, through reliable, repeatable creation of nanoscale features. Understanding the synthesis of nanoscale materials, via “top-down” and “bottom-up” strategies, allows researchers to assess the capabilities and limits inherent in both techniques(Wang X et al.,2002).

Novel materials are being developed with unique utility for ultrasensitive detection of biomolecules, for targeted delivery of therapeutic agents directly to affected cells and tissues in the body, and as a tissue scaffold to promote healing. Novel diagnostic methods and treatments are emerging from our increasing ability to control the synthesis of materials such as quantum dots, dendrimers, hydrogels and nanotubes, and to develop methods for optimizing the properties of these materials in living biological systems(Breedveld V. et al.,2004).In parallel, we are learning how to make nano materials that can be used safely and effectively for many other types of consumer products.

Nanotechnology provides the field of medicine with promising hopes for assistance in diagnostic and treatment technologies as well as improving quality of life. Humans have the potential to live healthier lives in the near future due to the innovations of nanotechnology. Some of these innovations include:
· Disease diagnosis
· Prevention and treatment of disease
· Better drug delivery system with minimal side effects
· Tissue Reconstruction

Nanoparticles can be designed with a structure very similar to the bone structure. An ultrasound is performed on existing bone structures and then bone-like Nanoparticles are created using the results of the ultrasound(Simon Timothy M et al.,1999). The bone-like nanoparticles are inserted into the body in a paste form. When they arrive at the fractured bone, they assemble themselves to form an ordered structure which later becomes part of the bone.

Another key application for nanoparticles is the treatment of injured spinal cord (Bundesen L. Q. et al., 2003). Samuel Stupp and John Kessler at Northwestern University in Chicago have made tiny rod like nano-fibers called amphiphiles .They are capped with amino acids and are known to spur the growth of neurons and prevent scar tissue formation. Experiments have shown that rat and mice with spinal injuries recovered when treated with these nano-fibers.

Currently, there are three techniques available for the synthesis of nanofibers: electrospinning, self-assembly, and phase separation. Of these, electrospinning is the most widely studied technique and also seems to exhibit the most promising results for tissue engineering applications (Ahmed, I et al., 2006, frenot A et al., 2003).Nanofibers synthesized by self-assembly and phase separation have had relatively limited studies that explored their application as scaffolds for tissue engineering (Hartgerink JD et al., 2002). Although there are a number of techniques for the synthesis of carbon nanofibers, such as chemical vapor deposition using a template method, catalytic synthesis (catalytic deposition, floating catalyst method, synthesis using radio frequency supported microwave plasmas, the description of each of these techniques is beyond the scope of this review (Hammel E et al., 2004). Therefore, for carbon and alumina nanofibers, the discussion is restricted to their applications in tissue engineering.

Electrospinning Technique
Electrospinning represents an attractive technique for the processing of polymeric biomaterials into nanofibers (Boudriot, U. and R. D. A. G. J. H. Wendorff 2006). This technique also offers the opportunity for control over thickness and composition of the nanofibers along with porosity of the nanofiber meshes using a relatively simple experimental setup.

Figure 1: An electrospinning device with a plate-shape metallic collector. The metallic plate can be either stationary or rotating to achieve different orientations of electrospun nanofibers (Reprinted from Tissue Engineering with permission of Mary Ann Liebert)

Although the electrospinning process is relatively simple in terms of its output, an understanding of the underlying mechanisms and several key processing conditions are essential for effective control of fiber properties. As the polymer solution is pumped to the spinneret tip, the high voltage induces charge accumulation to the solution. The droplet is then elongated into a conical shape, known as a Taylor cone due to the electrostatic repulsive force. Electrospinning is initiated when the repulsive force of the solution exceeds the surface tension of the droplet. A finely charged jet is formed at the tip of the Taylor cone. The jet is then stretched and accelerated, accompanied by solvent evaporation, and eventually collected by the target. Adjustment of the applied DC voltage, feeding rate, polymer solution viscosity and working distance can be used to control the morphology of the collected fibers. Here, some key effects of these processing parameters are briefly introduced; In most cases, increasing the applied DC voltage and resultant electric field will cause greater stretching of the polymer solution, which consequently reduces the diameter of the fibers. However, too high a voltage at a given feed rate will lead to a smaller and less stable Taylor cone, which can cause larger diameter bead formation along the fibers. The feed rate will also determine the volume of the polymer solution available for electrospinning at the spinneret tip. At a given voltage, higher feed rates generally yield fibers with larger diameters, although these rates are accompanied by slow solvent evaporation during flight time, leading to residual solvent and fusion of fibers. Working distance has less of an influence on fiber morphology, but smaller working distances results in an increased electric field strength and reduced flight time, which may also cause bead formation and fiber fusion.

The process of electrospinning is affected by two sets of parameters: system parameters and process parameters. System parameters such as polymer molecular weight and distribution determine the rate of degradation of nanofibers. System parameters such as polymer solution properties, i.e., viscosity, surface tension, and conductivity, determine the nanofiber diameter and reduce the possibility of bead formation. Process parameters such as orifice diameter, flow rate of polymer, and electric potential influence fiber diameter. Process parameters such as distance between capillary and metal collector determine the extent of evaporation of solvent from the nanofibers, and deposition on the collector, whereas motion of collector determines the pattern formation during fiber deposition. The systemic and process parameters vary with different polymeric systems and in most cases lend themselves to modification, thereby enabling tailoring of nanofibers for specific end uses (Fridrikh et al., 2003).


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