By: Tiffany Pham
Replacing members and changing parts naturally seems to be a practice in maintaining robots or marionettes. However, recent medical advancements have markedly demonstrated the potential in replacing and altering not robots, but the human body. From external body parts such as eyes to the skeletal structure of the human to the intricate configuration that is DNA, no part of the body is inaccessible to medical modification.
Artificial Retinas
Retinal degeneration can stem from disease or simply old age. Nonetheless, its effect is life-altering. As such, scientists are developing an ample range of medical devices designed to assist in visual impairment, namely artificial retinas.
Recent studies have demonstrated the utility of optogenetics in helping to restore damaged retinas. Researchers have combined semiconductor nanorods and carbon nanotube films to create a platform for light-induced neurostimulation. A plasma polymerized acrylic acid midlayer is intermingled between the nanorods and the nanotube films, encouraging covalent bonding between the two surfaces. The final product is a thin, wireless prosthesis which can potentially act in place of a damaged retina.
In conducted studies, some patients were able to use their artificial retinas for simple tasks, such as reading large letters and seeing-slow moving cars; however, other patients experienced no benefit. There is currently a large variation in the success of artificial retinas in individual subjects, presumably due to distinct neural connections and networking in each individual’s eye.
Despite the flaws in ongoing treatment, researchers still remain optimistic, continuing to tweak current systems and experimenting in different methods in retinal stimulation. One of the key challenges is being able to provide “images” with enough clarity the brain can identify what the patient is seeing.
3-D Printed Bone Replacement
Year after year, birth defects, injuries, and surgeries leave thousands of people in need of replacement bones in the head or face. Traditionally, treatment involves removing bone from one part of the body, carving it to the shape needed, and transferring it to the necessary region of anatomy. However, the drawbacks of this treatment are considerable; it is difficult to carve bones accurately and the removal of bone may create trauma in that region of the body.
In an attempt to combat the shortfalls of current treatment, biomedical engineer Warren Grayson and his team of researchers look to 3-D printing. Grayson took a material already used heavily in bone scaffolding research, the polyester PCL, and mixed it with pulverized cow bone or bone mixture; Grayson hypothesized that the bone powder would contain key structural proteins and growth factors that would render the composite more effective than PCL alone. The mixture was injected into a 3-D printer, which created a precise scaffold, or frame, of the needed bone, and coated with a healthy dose of stem cells, thrombin, and beta-glycerophosphate nutritional broth, designed to improve calcium deposition onto the scaffolds. The scaffolds were then transplanted into the part of the body with damaged bone and after about three weeks, new bone has grown atop the scaffold. The composite mixture used by Dr. Grayson and his fellow scientists led to significantly more bone growth in mice models then traditional PCL scaffolds.
In future studies, scientists hope to improve the composition of scaffold material to effect stronger and faster bone formation. They also want test composite materials made with powdered human bone, as well as experiment with additives that will allow scaffold implants to better acclimatize to the body.
Genome Editing
While human cells possess a volume as little as 30 micrometers cubed, each cell contains the entirety of its host’s genetic code. This code is established from birth and normally will not change. However, recent medical advancements have proved otherwise.
A genome editing tool by the name of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) was co-discovered by biologists Jennifer Doudna and Emmanuelle Charpentier. The system uses a key protein called Cas9 to lock on to certain parts of DNA and delete or edit them. Already an extremely widely-used gene-editing technique used in the laboratory to modify mammalian and bacterial genomes, some scientists are now looking further to adopt it for therapeutic purposes.While further research is needed to incorporate CRISPR into human therapeutics, the potential applications of genome editing are vast. CRISPR has already been used to correct the sickle-cell mutation in human cells grown in a petri dish.
Despite CRISPR’s current limits, the creation of the genome editing system has revolutionized pathways in modern gene therapy. As for what is planned for the progression of CRISPR, scientists have ambitions to apply CRISPR to more complex genetic diseases as well as the engineering of embryos during in vitro fertilization.
While the majority of this research has a long way to go before it is implemented outside of the lab, its applications possess great potential for the progression of the human body. Current medical studies are not only pushing the boundaries of past precedent, but provide a firm foundation for future advancement.