THE FUTURE OF MEDICINE Imagine a world where medicines can be guided to the exact place that they are needed in the body, where treatment is designed around the individual’s genetic makeup, and where spinal cord injuries can be repaired through a simple implant. It sounds like science fiction, but that world might be closer than you think, writes Delia du Toit.
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or centuries, smallpox ravaged humankind. During the 18th Century, 400 000 people died every year in Europe from the viral disease. The earliest evidence of skin lesions resembling those of smallpox was found on the faces of mummies from the Egyptian dynasties as early as 1570 to 1085 BC. Thanks to the development of a vaccine in the late 1800s, smallpox has since been wiped from the face of the earth. Such is the nature of medical innovation. Once a viable solution to a problem has been found, a disease can become part of the history books. It is not such a big reach, then, to assume that some of today’s biggest medical challenges such as hypertension, various cancers, and even certain forms of paralysis could be more easily treatable in the coming years. DEVELOPMENTS IN DRUG DELIVERY Professor Yahya Choonara, Chair and Head of Pharmacy and Pharmacology in the Faculty of Health Sciences as well as Principal Researcher and Co-Director of the Wits Advanced Drug Delivery Platform (WADDP), is one of the experts leading the charge in advances in drug delivery. The WADDP, he explains, focuses on three broad areas: advanced drug delivery that delivers medicine to specific sites in the body; nanomedicine, which reduces formulations to a nano scale for better targeting; and tissue engineering and regeneration, which includes such marvels as the 3D bioprinting of human tissue. “Advanced drug delivery is the science of developing 21st Century therapeutic interventions that ensure drugs can reach their target site of action in the body. This is beneficial because it improves the absorption and effect of medicines and significantly reduces side-effects. Some examples of targeted drug delivery technologies and nanomedicines include stimuli-responsive biomaterials, self-assembling molecules, ultrafast or extendedrelease delivery systems, and multilayered tablets that can be taken once but absorbed at different rates, and even the use of magnets to guide drugs to certain parts of the body.” The focus of current projects at the WADDP is on infectious diseases such as HIV and TB, targeted anti-cancer therapeutics, 3D-bioprinted wound healing systems, bio-inspired tissue engineering, and oral insulin systems. THRIVING TISSUE REGENERATION Merging nanomedicine with tissue engineering is changing the face of regenerative medicine. One such exciting development from the WADDP is the work
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An antimicrobial foam: The foam in this image has antimicrobial properties and has been designed for use in the oral cavity for periodontal diseases. of Dr Poornima Ramburrun, a researcher in biomaterial design and tissue regeneration, who designed a biodegradable hydrogel conduit used to repair peripheral nerve injuries. Currently, treatment for such cases involves taking nerves from another site in the patient’s body, creating two compromised sites. Alternatively, cadaveric donor tissues are used, which are sometimes rejected by the patient's body. This new device offers a better alternative, and a patent has already been granted in South Africa, Europe, the USA, and China. “Where nerves have been severed due to traumatic injuries such as vehicle accidents, or stab or gunshot wounds, the nerves have limited capacity and need assistance to regrow. This conduit acts as a bridge across that gap and protects growing nerves from the surrounding inflammatory environment, while releasing drugs to help the nerve fibres to regenerate. The device looks similar to the clear ink tube inside a pen, and it is sutured by a surgeon to either side of the damaged nerve,” she explains. Another very promising project is that of Dr Gillian Mahumane, who has developed a nano-reinforced hydro filled 3D scaffold for neural tissue engineering in the brain. She explains: “Brain tissue has a hard time repairing itself, sometimes causing a loss of function. So, if, for example, a small tumour is surgically removed, leaving a cavity, the brain tries to heal that tissue very quickly to restore the communication network, forming a scar that can block neurons. “This device mimics healthy tissue to trick the brain into not
