생체접착단백질 기반의 국소 항암치료용 기능성 접착 마이크로캐리어 개발

Abstract

Cancer therapies have evolved considerably in recent decades, improving the standard of comfort as well as survival rate of patients with cancer malignancies. Despite the favorable clinical success, non-specific cytotoxicity, insufficient persistence within cancer tissues, and poor bioavailability have still remain as challenges. Therefore, rational design of functional carriers is required for locoregional cancer treatments which can allow prolonged and targeted delivery of anti-cancer therapeutics while simultaneously reducing non-specific off-target side effects. To develop therapeutic vehicles with superior tissue adhesion, we employed bioengineered MAPs as primary composition materials, which have been considered as promising biomaterials for tissue engineering and biomedical applications by virtue of their excellent biocompatibility and underwater tissue adhesiveness. In this dissertation research, we developed two types of functional adhesive microcarriers using bioengineered MAPs for successful locoregional anticancer therapy: MAP microspheres (MSs) for site-specifically targeted cancer chemotherapy and MAP microcapsules (MCs) for natural killer (NK) cells-mediated cancer immunotherapy. First, we fabricated MAP MSs and MAP MCs via droplet microfluidics technique by generating single emulsion (water-in-oil (W/O)) and multi-compartmental triple emulsion (water-in-oil-water-in-oil (W/O/W/O)), respectively. Droplet microfluidics could allow exquisite control over the flows of multiple fluids in microscale, enabling the fabrication of sophisticated microparticles with precisely controlled compositions and structures in a customized manner. Microfluidically produced MAP MSs and MCs displayed highly homogeneous monodisperse morphology and robust mechanical stability as well as cytocompatibility. Importantly, the release behavior of therapeutic agents from the MAP MSs was notably consistent and reproducible, indicating that the MSs can be finely tunable for achieving desired properties to meet different application purposes. MAP MCs also exhibited release capability of encapsulated macromolecules, which can be varied as immune-modulating antibodies or proteinaceous molecules secreted from encapsulated therapeutic cells. Therefore, MAP microparticles produced by droplet microfluidics can be promisingly employed as functional therapeutic vehicles of bioactive substances or cells. Next, we developed MAP MSs into magnetically guidable, tissue-adhesive microcarriers for site-specific locoregional delivery of doxorubicin (DOX), a chemotherapy drug used for a variety of types of cancers. The MAP MSs embedded with iron oxide (IO) nanoparticles (MAP@IO MSs) were initially targeted to a specific region by a magnetic field and retained for a prolonged period under hydrodynamic fluid-flowing environment even after removal of the external magnetic field by due to their superior underwater adhesive property. These MSs could allow a sustainable DOX release profile and effective cytotoxicity toward cancer cells. We considered that the magnetic guidance of the MAP@IO MSs could be applied as an effective strategy for targeted therapeutics delivery to a specific region in hydrodynamic physiological environment such as the esophageal epithelium. Consequently, MAP-based adhesive microspheres allow magnetic guidance and persistent retention in a collaboratively balanced manner, and thus can be extensively employed for a targeted locoregional treatment of esophageal cancer with further expansion to various tubular organ-associated diseases. Finally, we applied MAP MCs for localized NK cells-mediated cancer immunotherapy. MAP MCs with aqueous core environment were highly beneficial for encapsulation of immune cells which grow in suspension. Therefore, NK cells-encapsulated MAP MCs (MAP@NK MCs) could allow superior proliferation of encapsulated NK cells by virtue of hydrated core environment and mass transport through semi-permeable shell layer. Importantly, soluble factors with anti-cancer functionality (i.e., IFN-γ, granzyme B and perforin) secreted from encapsulated NK cells could be sustainably released from the MAP@NK MCs. As a result, the MAP@NK MCs demonstrated effective in vitro and ex vivo therapeutic efficacy. Consequently, the MAP MCs with aqueous core composition and strongly adhesive and semi-permeable shell layer have practical applicability for immune cells-mediated localized cancer immunotherapy. Collectively, we developed two types of bioengineered MAPs-based functional micro-vehicles for spatiotemporally controllable therapeutic system. MAP microcarriers could provide targeted and prolonged administration of cancer-eradicating bioactive agents to a cancer tissue, significantly improving anticancer functionality. These mirocarriers also showed superior biocompatibility, sustainable therapeutics release, and robust underwater adhesive properties. Thus, we suggest that MAP-based adhesive microparticles can be extensively employed as functional vehicles of a plethora of chemo- and immune-therapeutic agents for effective locoregional and sustained cancer therapy.