Key Elements For Tissue And Organ Regeneration

Tissue engineering is an emerging interdisciplinary field that uses principles from engineering, biology and chemistry in an effort towards tissue regeneration. The main draw of tissue engineering is the regeneration of a patient’s own tissues and organs free from low biofunctionality and poor biocompatibility and serious immune rejection. As medical care continues to improve and life expectancy continues to grow, organ shortages become more problematic.(Manufacturing living things) According to organdonor.gov, a patient is added to the waiting list every 10 minutes and an average of 18 people die everyday waiting for an organ donation. The “nirvana” of tissue engineering is to replace the need for organ donation altogether. This could be achieved using scaffolding from

The second type of tissue found in the body is connective tissue. They lie beneath the epithelial tissue helping to connect different part of the internal structure, the cells are more widely separated from each other then in epithelial tissue. The intercellular substance known as the matrix is found in considerably large amounts. Within the matrix there are usually fibres which may be a jelly like consistency or dense and rigid depending on the type, function and positioning of the tissue. Theses fibres form a supporting system for cells to attach to. The major functions of connective tissue are to transport materials, give structural support and protection. The types of connective tissue that will be explained are blood, bone, cartilage, bone, areolar tissue and adipose tissue.

In the past, the only way to replace diminished cells, tissues, and organs was from organ transplantation. An organ donor was needed, and the tissues would be surgically removed from the donated body and placed into the recipient. Due to the current research being conducted, it is believed that tissue engineering and organ printing can contribute to the process of improving and saving lives.

The inclusion of nanoparticles into the biopolymer matrix has the dual objective of improving the mechanical properties as well as of incorporating nanotopographic features that mimic the nanostructure of natural tissue (7, 88-91)., the role of the scaffolds is being extended from being a mere mechanical support to include intelligent surfaces capable of providing both chemical and physical signals to guide cell attachment and spreading, possibly influencing also cell differentiation (92) (see also Figure

Cornell’s Lawrence Bonassar used 3D photos of human ears to create ear molds. These molds were then filled with a gel containing bovine cartilage cells suspended in collagen, which held the shape of the ear while cells grew their extracellular matrix. Bonassar and his team have since gone on to 3D print intervertebral discs to treat major spinal complications, while researchers at Princeton have 3D printed their own collagen ear, this time, with built-in electronic components for superhuman hearing.

Autologous, chondrocytes, embolization and hematopoietic all terminology used to explain stem cell therapy. Stem cells are the future of medicine; in fact, many scientists have come up with cures using stem cells including increasing liver regeneration. Why must people increase liver regeneration? People who suffer from liver cirrhosis cannot regenerate new liver cells due to the fact that there liver is producing scar tissue. Stem cell therapy, an intensive tedious process captivating researchers everywhere, enigmatic research that is paving the way for the cure of liver disease.

It is made up both of specialized cells that affix to other tissues as well as what is known as the extracellular matrix. Its most distinctive attribute, this matrix is made up of fluid; gound substance, a gel that contains nutrient molecules like hyaluronic acid that are composed of carbohydrates and protein; and protein-based fibers like collagen and elastin. The fibers give the tissue its denseness and strength and are what helps connective tissue function properly.

Bioprinting offers the ability to create a 3D biomimetic tissue by patterning cells and, in some approaches, multiple cell types with precise and reproducible spatial control. In order to create these organs a researcher must start off with a bioink consisting of compounds with a chemical structure consisting of polysaccharides and/or proteins. Some of the compounds include, but are not limited to agar, collagen, silk, elastin, and chitosan. These bioinks are then infused with additives that include growth factors, cytokines, and extracellular matrix (Bioprinting 4-12). Bioprinting then “moves from the laboratory to the clinic sources, clinical grade cells will be necessary to support the assembly of different constructs” This is where stem cells from the patient, if possible, are utilized to prevent the use of immunosuppressive drugs. (Bioprinting 4-12). Once everything is loaded into the biopen, it is then loaded into the bioprinter (fig 1, 2). Researchers are then able to make tissues, organs, and many other structural components.

The whole idea of Regenerative Medicine is based on regenerating damaged or defected tissues or organs. This is made by stimulating organs to heal themselves.

Treating peripheral nerve injury is a major clinical challenge owing to the limited ability of the peripheral nerves to regenerate itself. Conventional treatment methods such as coaptation, autografting and xenografting possess inherent drawbacks such as reduced nerve stretching capacity, neuroma formation etc. To overcome these limitations, artificial nerve grafts employing natural or synthetic biomaterials are being developed. Axonal guidance structures and luminal fillers such as Schwann cells, stem cells, or nerve growth factors are also incorporated in the grafts to enhance their functionality. This paper reviews some of the biomaterials used in peripheral nerve regeneration, various modifications incorporated in them and their efficiency

In addition, the biomimetic glue is also able to transport potent drugs or even genes to affected areas where they are needed, whilst fixing the targeted area simultaneously. They can deliver pain killers, antibiotics, anti-inflammatory medicines or even stem cells to the sites where the adhesive is applied, making it a great choice for medical procedures involving the repair of broken bone (Noria Corporation, n.d.). Utilizing biomimetic adhesives for the repair of broken bones replaces the need of metal screws and pins which are potentially hazardous and are not always effective, especially for small fractures, making the synthetic adhesives a safer and better alternative (APAGE, 2013). Scientists have also taken an inert polymer naturally found in humans called hyaluronic acid-catechol (fig. 6) and the inert polymer found in algae called alginate catechol (fig.7), and modified them into an adhesive gel that mimics the structure of the proteins in mussel glue by adding

"autologous tissue, indistinguishable in form and function from its native counterpart. The cardiovascular system has been identified as a target for tissue engineering since the inception of the field and the potential of tissue engineering to benefit patients with cardiovascular disease is even more relevant in the present day. Currently, cardiovascular disease accounts for 20% of global mortality and is the most common cause of death in adults within the United States (47). While significant strides have been made in medical management, surgical intervention requiring the use of prosthetic implants continues to be critical in many adult

TransCyte is a temporary, bioactive synthetic covering with a similar structure to Biobrane, with an addition of fibroblasts. Like Biobrane, it is also used as covering for burn patients before autografting or for patients with partial thickness burns who do not require autografts[11][12]. TransCyte consists of two layers, a silicone outer layer and an inner nylon mesh seeded with fibroblasts. The outer silicone layer is a semipermeable membrane, containing a series of laser-punched holes that allow excess fluids to be drained[13]. The inner nylon mesh membrane is coated with porcine collagen peptides, creating the base onto where the neonatal fibroblasts can be cultured, since collagen is a main component of the skin. In order to seed the fibroblasts within the nylon mesh, the entire membrane, silicone outer layer included, was placed inside a specially designed bioreactor. This bioreactor provided a continuous, constant flow of fibroblasts at a rate of about

Lately, there is an emerging innovation whereby organs are created to form and increase in size by a process of inorganic accretion, from the patient’s cell. This field of medicine is known as the regenerative medicine. In addition to this, there are basically various types of regenerative medical

As stated previously, the instructive and responsive function of the ECM is essential for normal cellular development. Introducing bioactive molecules in a synthetic scaffold is very important to mimic the natural ECM. In general, there are two ways to add bioactive molecules to a scaffold. This can be done by either mixing the bioactive compounds and the polymers used for electrospinning or introducing covalent modifications to the polymers. Mixing bioactive compounds and base materials often result in a highly dynamic but uncontrollable release of bioactive molecules. Covalent modifications result in stable incorporation of bioactive molecules, but these systems lack essential dynamics. However, when covalent modifications respond to environmental stimuli, bioactive compounds can be released in the correct spatio-temporal manner. Several instructive and responsive scaffolds have been developed and studied (Bouten et al., 2011). Zhang et al. (2012) produced a dual-delivery electrospun scaffold with controlled release of two different growth factors. A hydrogel was used to encapsulate the growth factors. A new electrospinning technique, co-axial spinning, produced combined layers of hydrogel with polymers. With this technique, it is possible to combine hydrogel encapsulating growth factors and electrospun polymers during the electrospinning process. The degradation rate of the polymers controls release of the growth factors after electrospinning. Also,