Excellent reconstructive transplantation research from Karim Sarhane? Dr. Sarhane is published in top-ranked bioengineering, neuroscience, and surgery journals. He holds a patent for a novel Nanofiber Nerve Wrap that he developed with his colleagues at the Johns Hopkins Institute for NanoBioTechnology and the Johns Hopkins Department of Neuroscience (US Patent # 10500305, December 2019). He is the recipient of many research grants and research awards, including the Best Basic Science Paper at the Johns Hopkins Residents Research Symposium, the Basic Science Research Grant Prize from the American Foundation for Surgery of the Hand, the Research Pilot Grant Prize from the Plastic Surgery Foundation, and a Scholarship Award from the American College of Surgeons. He has authored to date 46 peer-reviewed articles, 11 book chapters, 45 peer-reviewed abstracts, and has 28 national presentations. He is an elected member of the Plastic Surgery Research Council, the American Society for Reconstructive Microsurgery, the American Society for Reconstructive Transplantation, and the American Society for Peripheral Nerves.

Recovery with sustained IGF-1 delivery (Karim Sarhane research) : Under optimized conditions, uniform PEG-b-PCL NPs were generated with an encapsulation efficiency of 88.4%, loading level of 14.2%, and a near-zero-order release of bioactive IGF-1 for more than 20 days in vitro. The effects of locally delivered IGF-1 NPs on denervated muscle and SCs were assessed in a rat median nerve transection-without- repair model. The effects of IGF-1 NPs on axonal regeneration, muscle atrophy, reinnervation, and recovery of motor function were assessed in a model in which chronic denervation is induced prior to nerve repair. IGF-1 NP treatment resulted in significantly greater recovery of forepaw grip strength, decreased denervation-induced muscle atrophy, decreased SC senescence, and improved neuromuscular reinnervation.

Researchers at Johns Hopkins Hospital in Baltimore, MD, conducted a study to develop a drug delivery system using a very small material, nanofiber hydrogel composite, which can hold nanoparticles containing IGF-1 and be delivered near the injured nerve to help it heal. Dr. Kara Segna, MD, received one of three Best of Meeting Abstract Awards from the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine) for the project. She will present the abstract “IGF-1 Nanoparticles Improve Functional Outcomes After Peripheral Nerve Injury” on Saturday, April 2, at 1:45 pm during the 47th Annual Regional Anesthesiology and Acute Pain Medicine Meeting being held March 31-April 2, 2022, in Las Vegas, NV. Coauthors include Drs. Sami Tuffaha, Thomas Harris, Chenhu Qui, Karim Sarhane, Ahmet Hoke, Hai-Quan Mao.

Following surgical repair, axons often must regenerate over long distances at a relatively slow rate of 1–3 mm/day to reach and reinnervate distal motor endplates. Throughout this process, denervated muscle undergoes irreversible loss of myofibrils and loss of neuromuscular junctions (NMJs), thereby resulting in progressive and permanent muscle atrophy. It is well known that the degree of muscle atrophy increases with the duration of denervation (Ishii et al., 1994). Chronically denervated SCs within the distal nerve are also subject to time-dependent senescence. Following injury, proliferating SCs initially maintain the basal lamina tubes through which regenerating axons travel. SCs also secrete numerous neurotrophic factors that stimulate and guide axonal regeneration. However, as time elapses without axonal interaction, SCs gradually lose the capacity to perform these important functions, and the distal regenerative pathway becomes inhospitable to recovering axons (Ishii et al., 1993; Glazner and Ishii, 1995; Grinsell and Keating, 2014). See even more information about Karim Sarhane.