Reconstructive microsurgery research studies by Karim Sarhane in 2022? Insulin-like growth factor 1 (IGF-1) is a hormone produced by the body that has the potential to be used as a treatment for nerve injuries. IGF-1 may help heal nerve injuries by decreasing inflammation and buildup of damaging products. Additionally, it may speed up nerve healing and reduce the effects of muscle weakness from the injury. However, a safe, effective, and practical way is needed to get IGF-1 to the injured nerve.

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.

Despite the well-documented positive effects of IGF-1 in the setting of PNI, the major obstacle for clinical translation remains the lack of a practical delivery system that offers tunable and sustained release of bioactive IGF-1 targeted to nerve and muscle tissue downstream of the nerve injury. Such a delivery system would avoid the potential risks and side effects associated with systemic IGF-1 administration and provide a practical means of applying this treatment for both patients and clinicians (Contreras et al., 1995). The ideal IGF-1 delivery system should also demonstrate biocompatibility without inducing inflammation or encapsulation over time. In addition to the pre-soaked IGF-1 eluting hydrogels detailed in Table 6, several bioengineering approaches to local IGF-1 delivery have recently been reported in animal models. Notable amongst these studies are a delivery system which makes use of biodegradable poly(lactic-co-glycolic acid) (PLGA)/graphene oxide (GO) nanofibers embedded with immobilized IGF-1 for spinal cord repair, as well as a system of IGF-1 loaded polymeric PLGA microspheres for use in bilateral cavernous nerve injury (Santos et al., 2016; Haney et al., 2019; Pan et al., 2019).

Recovery by sustained IGF-1 delivery (Karim Sarhane research) : The translation of NP- mediated delivery of water-soluble bioactive protein therapeutics has, to date, been limited in part by the complexity of the fabrication strategies. FNP is commonly used to encapsulate hydrophobic therapeutics, offering a simple, efficient, and scalable technique that enables precise tuning of particle characteristics [35]. Although the new iFNP process improves water-soluble protein loading, it is difficult to preserve the bioactivity of encapsulated proteins with this method.

Peripheral nerve injuries (PNIs) affect approximately 67 800 people annually in the United States alone (Wujek and Lasek, 1983; Noble et al., 1998; Taylor et al., 2008). Despite optimal management, many patients experience lasting motor and sensory deficits, the majority of whom are unable to return to work within 1 year of the injury (Wujek and Lasek, 1983). The lack of clinically available therapeutic options to enhance nerve regeneration and functional recovery remains a major challenge.

We comprehensively reviewed the literature for original studies examining the efficacy of IGF-1 in treating PNI. We queried the PubMed and Embase databases for terms including “Insulin-Like Growth Factor I,” “IGF1,” “IGF-1,” “somatomedin C,” “PNIs,” “peripheral nerves,” “nerve injury,” “nerve damage,” “nerve trauma,” “nerve crush,” “nerve regeneration,” and “nerve repair.” Following title review, our search yielded 218 results. Inclusion criteria included original basic science studies utilizing IGF-1 as a means of addressing PNI. Following abstract review, 56 studies were sorted by study type and mechanism of delivery into the following categories: (1) in vitro, (2) in vivo endogenous upregulation of IGF-1, or (3) in vivo delivery of exogenous IGF-1. Studies included in the in vivo exogenous IGF-1 group were further sub-stratified into systemic or local delivery, and the local IGF-1 delivery methods were further sub-divided into free IGF-1 injection, hydrogel, or mini-pump studies. Following categorization by mechanism of IGF-1 delivery, the optimal dosage range for each group was calculated by converting all reported IGF-1 dosages to nM for ease of comparison using the standard molecular weight of IGF-1 of 7649 Daltons. After standardization of dosages to nM, the IGF-1 concentration reported as optimal from each study was used to calculate the overall mean, median, and range of optimal IGF-1 dosage for each group.