Osseointegration of osteoporotic bone implants: Role of stem cells, Silica and Strontium - A concise review

Abstract

Osteoporotic fracture treatment has become a skeletal reconstructive challenge due to accelerated bone turnover and impaired bone regeneration potential. Poor osseointegration ability of the osteoporotic bone usually results in implant pull out and failure. Adoption of conventional bone fracture treatment strategies like autografts and allografts have limited applications in such pathological conditions. Hence biomaterials functionalised with therapeutic ions or drugs may be adopted to aid the delivery of therapeutic factors at the defect site to promote bone healing and implant integration, towards functional restoration of the fractured bone. This concise review narrates on improving the osseointegration ability of biomaterials using functional ions like Silica and Strontium. Silica based bone substitutes are known to promote bone healing in non pathological conditions. Further, Strontium based drugs show significant effects in the prevention and treatment of osteoporotic bones. In addition, stem cell therapy has become the focus of orthopaedic research attributed to its ability to restore and accelerate the bone healing process, but the clinical application of stem cells in osteoporotic condition is scarce. Present review suggests a novel strategy of combining the therapeutic potential of functional ions like Silica, Strontium and stem cells within a single implant unit to facilitate osseointegration and osteogenesis, so as to reduce the chances of implant rejection/pull out and encourage osteoporotic bone re-union.

Advances in Osteoporotic Bone Tissue Engineering

“…Inflammatory cells (macrophages, monocytes, lymphocytes, and polymorphonuclear cells) and fibroblasts infiltrate bone tissue in a process mediated by prostaglandins [ 11 ]. Throughout fracture repair, mesenchymal stem cells (MSCs) from the bone marrow are engage at the fracture site in interaction with the local cells influencing the healing efficacy [ 7 ]. The emergence of intramembranous bone starts right away at the cortical tissue and periosteum.…”

“…Calcium phosphate scaffolds show the capacity to promote osteogenesis and osteointegration, due to their surface charge, and, also, their chemistry and topography [ 4 ]. HA coated implants are proven to promote osteointegration capacity of inert metals [ 7 ] but some pioneering works were reported related to COLL/HA composite deposition by using MAPLE [ 54 ]. Due to its high biocompatibility, bioactivity, osteoconductive and/or osteoinductive capacity (in certain conditions), nontoxicity, nonimmunogenic properties, and noninflammatory behavior, HA is available and used as a bone filler and as coatings on prostheses, [ 4 ].…”

“…Progresses in medicine have raised both life expectancy globally and age-connected illnesses liable for declining life quality of the elderly [ 4 ], with one of the most common and wide-spread skeletal disease being osteoporosis [ 5 ], with an increase in osteoporotic fracture in both genders with age [ 6 ]. Each year, almost 200,000,000 patients are confirmed as osteoporotic and around 9,000,000 osteoporotic fractures happen globally [ 5 ], with a rising number of elderlies being prone to fragility fractures [ 7 ]. Bone lesions are difficult for the elderly and can lead to morbidity and substantial socioeconomic costs creating a demand for new and efficient regenerative strategies and better results for patients [ 4 ] as the incidence of osteoporosis is predicted to further rise worldwide [ 5 ].…”

Study of Sr–Ca–Si-based scaffolds for bone regeneration in osteoporotic models

“…4,5 The representative treatment is strontium ranelate; however, a series of undesirable side effects cannot be ignored for long-term systematic treatment. 6 Studies have indicated that strontium (Sr) serves as one of the most efficient trace elements for bone metabolism due to its strong bone-seeking properties, 7 and it can also inhibit osteoclast function. 8,9 Nonetheless, while studies have mainly focused on the applications of pharmacological agents in the field of osteoporosis, less attention has been paid to site reconstruction of osteoporotic-related bone defects or fractures.…”

Comparing bone tissue engineering efficacy of HDPSCs, HBMSCs on 3D biomimetic ABM-P-15 scaffolds in vitro and in vivo

“…The increasing clinical demand for bone regeneration and repair in the context of our ageing population poses a challenge both to healthcare providers and society (Iaquinta et al 2019 ). There is also increasing demand for the implant osseointegration, which is crucial for successful implantology in both orthopaedics and dentistry (Chandran and John 2019 ; Liu et al 2019 ). Tissue engineering provides a promising strategy to meet this clinical demand by developing functional bone construct using stem/stromal cells, biomimetic biomaterial scaffolds, with/without growth factors (Abdulghani and Mitchell 2019 ).…”