Design of Drug Loaded Double Layered Microparticles
Mentor 1
Priyatha Premnath
Start Date
28-4-2023 12:00 AM
Description
Over 2 million bone fractures occur in the United States each year, with about 900,000 requiring hospitalization or other additional care to recover [1]. The annual cost of fracture care exceeds $17 billion and is expected to increase with the growing geriatric population [1,2]. Current treatments for severe fractures include bone fixation devices, grafts of healthy bone, and various biomaterial scaffolds loaded with osteogenic growth factors. Despite the advantages of these treatments, there still remains the risk of infection, nonunion of the bone, and long recovery times [3]. Recent developments in biomaterial approaches attempt to facilitate fracture healing in vivo through the delivery of drugs or other agents that promote the natural healing process [3,4]. Growth factors, hormones, or other drugs that promote bone healing have been encapsulated in microparticle carriers synthesized from biodegradable materials, resulting in improved osteogenesis outcomes [3-5]. Similarly, microparticle carriers have been developed to promote chondrogenesis for cartilage regeneration applications [6]. However, approaches that target both chondrogenesis and osteogenesis for fracture healing are lacking. Here, we synthesize double layered microparticles with an outer shell of polylactic-co-glycolic acid (PLGA) and an inner core of polylactic acid (PLLA), loaded with Cobalt(II) chloride (CoCl2) and hydroxyapatite (HAP), respectively with the aim of promoting both chondrogenic and osteogenic effects crucial to bone healing [7]. It is widely acknowledged that Co2+ ions contribute to a hypoxic environment, important to promoting chondrogenesis as well as osteogenic effects during the inflammatory stage of bone healing, while HAP promotes osteogenesis. SEM-EDS was used to assess the location of CoCl2 and HAP within the microparticles and current studies aim to elucidate their release rates in vitro.
Design of Drug Loaded Double Layered Microparticles
Over 2 million bone fractures occur in the United States each year, with about 900,000 requiring hospitalization or other additional care to recover [1]. The annual cost of fracture care exceeds $17 billion and is expected to increase with the growing geriatric population [1,2]. Current treatments for severe fractures include bone fixation devices, grafts of healthy bone, and various biomaterial scaffolds loaded with osteogenic growth factors. Despite the advantages of these treatments, there still remains the risk of infection, nonunion of the bone, and long recovery times [3]. Recent developments in biomaterial approaches attempt to facilitate fracture healing in vivo through the delivery of drugs or other agents that promote the natural healing process [3,4]. Growth factors, hormones, or other drugs that promote bone healing have been encapsulated in microparticle carriers synthesized from biodegradable materials, resulting in improved osteogenesis outcomes [3-5]. Similarly, microparticle carriers have been developed to promote chondrogenesis for cartilage regeneration applications [6]. However, approaches that target both chondrogenesis and osteogenesis for fracture healing are lacking. Here, we synthesize double layered microparticles with an outer shell of polylactic-co-glycolic acid (PLGA) and an inner core of polylactic acid (PLLA), loaded with Cobalt(II) chloride (CoCl2) and hydroxyapatite (HAP), respectively with the aim of promoting both chondrogenic and osteogenic effects crucial to bone healing [7]. It is widely acknowledged that Co2+ ions contribute to a hypoxic environment, important to promoting chondrogenesis as well as osteogenic effects during the inflammatory stage of bone healing, while HAP promotes osteogenesis. SEM-EDS was used to assess the location of CoCl2 and HAP within the microparticles and current studies aim to elucidate their release rates in vitro.
