The main focus of research in our laboratory is the development of novel methods for controlled delivery of bioactive agents. Four areas are being explored:
Genetically engineered polymers for gene delivery
Recombinant DNA technology has enabled the synthesis of protein-based polymers with precisely controlled structures. Control over polymer structure at the molecular level has important implications for controlled delivery applications. The potential of recombinant silk-elastinlike protein polymers (SELPs) for matrix-mediated gene delivery is being explored. The idea is that by using recombinant techniques it is possible to systematically correlate polymer structure with gene release and transfer. Our main focus is on gene therapy applications in the treatment of head and neck cancer. For a recent article see [Price R, Poursaid A, Cappello J, Ghandehari H. J Control Release, ;213:96-102, 2015 Jun 18]. More recent efforts focus on design of recombinant polymers as liquid embolics [Poursaid A, Price R, Tiede A, Olson E, Huo E, McGill L, Ghandehari H, Cappello J. Biomaterials, 57:142-52, 2015 Jul] and for prophylactic treatment of radiation-induced proctitis [Jensen MM, Jia W, Isaacson KJ, Schults A, Cappello J, Prestwich GD, Oottamasathien S, Ghandehari H. J Control Release. 2017 [Epub ahead of print]].
Water-soluble polymers for targeted delivery
Targeted delivery of bioactive agents by water soluble polymers can increase efficacy and reduce toxicity. The synthesis, characterization and biological evaluation of targetable N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers for targeted delivery to angiogenic blood vessels of solid tumors have been investigated [D. Pike, H. Ghandehari, Advanced Drug Delivery Reviews, 62:167-183, 2010]. More recent efforts focus on gold nanorod-mediated hyperthermia [A.J. Gormley, N. Larson, S. Sadekar, R. Roinson, A. Ray, and H. Ghandehari, Nano Today, 7:158-167, 2012; N. Larson, A. Gormley, N. Frazier, and H. Ghandehari, Journal of Controlled Release, 170:41-50, 2013]; Robinson R, Gerlach W, Ghandehari H. J Control Release. 2015 Dec 28;220(Pt A):245-52], and High Intensity Focused Ultrasound [Frazier N, Payne A, Dillon C, Subrahmanyam N, Ghandehari H. Nanomedicine. 2017 Apr;13(3):1235-1243] for enhanced delivery of macromolecular therapeutics to solid tumors.
Poly(amidoamine) dendrimers for oral delivery
Due to their large size water soluble polymers generally need to be administered intravenously. It would be desirable to develop polymeric carriers that are orally bioavailable. Nano-scale poly(amidoamine) (PAMAM) dendrimers of appropriate size, charge and concentration can be transported across the gastrointestinal epithelial cells with minimal or no toxicity. The influence of variables such as size, charge, surface functionality and drug loading on the mechanism and rate of transport of PAMAM dendrimers across epithelial barriers has been investigated. More recent efforts focus on in vivo oral bioavailability of PAMAM dendrimers and their transepithelial transport across isolated intestinal tissue. For a recent articles on this topic see [Hubbard D, Enda M, Bond T, Moghaddam SP, Conarton J, Scaife C, Volckmann E, Ghandehari H. Mol Pharm. 2015 Nov 2;12(11):4099-107; Yellepeddi VK, Ghandehari H. Tissue Barriers. 2016 Apr 6;4(2):e1173773].
Nanotoxicology of dendritic and inorganic constructs
Recent advances in nanotechnology have enabled the fabrication of inorganic nanoconstructs with defined shape, size, and surface functionality. Examples of such constructs include inorganic nanorods and nanospheres. Efforts are directed at evaluating the influence of geometry and surface functionality on biocompatibility and biodistribution of silica and gold nanoparticles, as well as poly(amido amine) dendrimers. In addition, research in this area is focused on design and development of silica nanoparticles with controlled degradation rate for delivery of bioactive agents. For recent articles see [T. Yu, K. Greish, L. McGill, A. Ray, and H. Ghandehari, ACS Nano, 6:2289-2301, 2012; Herd HL, Bartlett KT, Gustafson JA, McGill LD, Ghandehari H. Biomaterials, 53:574-82, 2015; Hadipour Moghaddam SP, Saikia J, Yazdimamaghani M, Ghandehari H. ACS Appl Mater Interfaces. 2017 [Epub ahead of print]]