Nano-scaffold
Nano-scaffolding or nanoscaffolding is a medical process used to regrow tissue and bone, including limbs and organs.
[1] Developed by the American military, the medical technology uses a microscopic apparatus made of fine polymer fibers called a scaffold.
[3] Historically, research on nano-scaffolds dates back to at least the late 1980s when Simon showed that electrospinning could be used to produce nano- and submicron-scale polymeric fibrous scaffolds specifically intended for use as in vitro cell and tissue substrates.
Electrospinning allows the construction of these webs to be controlled in the sense of the tube's diameter, thickness, and the material being used.
Stem cells that are attached to a scaffold are shown to be more successful in adapting to their environment and performing the task of regeneration.
The ability to be able to repair damaged nerves is the greatest challenge and prize for many researchers as well as a huge step for the medical field.
The technology however, is still in its infancy and is still not capable of regenerating complex organs like a heart, although it can already be used to create skin, bone and nails.
[8] Nanoscaffolding provides a large surface area for the material being produced, along with changeable chemical and physical properties.
[9] Tissue engineering applications are designed to overcome hurdles associated with allotransplantation, which include unavailable donors, complex surgeries, and postoperative care.
Natural biomaterials risk a negative immune response in the implantation host due to the allogeneic or xenogeneic source.
To fabricate with solid free-form or rapid prototyping, methods such as laser sintering, stereolithography, and 3D printing have been utilized.
With fabricating allowing an intricate structure formation, the nano-scaffolds utilizing this method can be tuned to resemble specific tissue ECMs.
To utilize the ECM from allogeneic or xenogeneic tissues the cellular antigens must be removed due to implant recipient immune response.
Once initiated by pH, temperature, ionic strength, or light control, the biomaterials self-assembles into a solid polymer meshwork.
This method contains low mechanical properties due to the highly moldable structure of the nano-scaffold and is not ideal for load-bearing applications.
Gold nanoparticles within nano-scaffolding induces osteogenic differentiation due to signal transduction from mechanical stimuli.
Zinc nanoparticles within nano-scaffolding decrease the number of reactive oxygen species, which are associated with failure of implants due to bacterial infection.
Electrospinning systems consist of high voltage power, material delivery, and fiber collection units.
The high voltages produce charged polymer solution, which exits from the delivery unit in a jet form.
The morphology of fibers fabricated through electrospinning varies with the solution properties of the polymer, hydrostatic pressure, temperature, and humidity.
Electrospinning nanofibers limits the three-dimensional capabilities of the nano-scaffold, which decreases cell differentiation and gene expressions.
To appropriately emulate the complexity of native tissue and extracellular matrix(ECM) architecture, the adoption of nanotechnology becomes an integral part of scaffold implant production.
Airbrushing is a technique for fiber fabrication that involves two parallel concentric fluid streams; a polymer dissolved in a volatile solvent and a pressurized gas that flows around the polymer solution, generating fibers that are deposited in the direction of gas flow.
Phase separation approximates more to conventional foams with larger pore sizes, implying that this method would be prone to cell infiltration, making it favorable for tissue engineering..
The technique allows precise spacing and orientation of fibers into planar or non-planar structures using a wide spectrum of polymers.
Nano-fibrous scaffolds, created from STEP techniques, have the ability to be used for a wide range of applications in tissue engineering By 2012 the US over half a million people receive bone defect repairs yearly with an estimated cost of $2.5 million and has doubled in recent years.
However, large scale defects, inflammations caused by accidents, infections and tumors make it difficult for the bone to heal, requiring external interventions.
The growing shortage of donors, rejection of transplants, and mechanical failure have made it difficult to have lasting solutions.
Novel biomaterial and tissue engineering strategies have been developed recently to address the need, mainly centering around formulating nanoscaffolds that fill the gap created in the injury site and that foster a pro-regenerative environment that help to facilitate restoration of the spinal cord structure and function.
Collagen is also a major component of the extracellular matrix, most importantly in central nervous tissue where it has good histocompatibility and supports adhesion and growth.
