Incorporation of boron in the bioactive glass composition 6P55 as a coating for Ti6Al4V for dental and orthopedic implant applications
Bioactive glasses were introduced to the world in 1969 by the late Dr. Larry Hench when he developed the novel glass composition 45S5, commercially known as Bioglass®, through discovering the optimized ternary Na2O–CaO–SiO2 structure and incorporating phosphorous into that matrix. This came about after an enlightening, in-depth conversation with a soldier during World War II while on a train to a conference. They discussed the common types of injuries that were sustained, often resulting in avoidable amputation because there was no treatment available at that time to prevent it. That conversation led to the idea to develop a material capable of interacting with the bodily environment, thus facilitating cellular and bone regeneration. With the invention of the novel Bioglass® composition, Hench observed that his creation mimicked many properties of normal bone and stimulated the regrowth of bone between fractures by forming a hydroxyapatite structure on its surface, once exposed to the aqueous bodily environment, and therefore allowing it to bond with both hard and soft tissue, with less chance of rejection. Since then, Bioglass® has been used in bone tissue engineering, drug delivery, as a graft material, endosseous implants, remineralizing agent, and as an antibacterial agent. Years later, other scientists and engineers would use this novel composition as the foundational concept for numerous families of bioactive glass-ceramics.
Our research focuses on the application of bioactive glasses as coatings for implants. In conjunction with Dr. Du’s laboratory in the Materials Science and Engineering department, our lab aims to develop a suitable glass coating for the titanium alloy, Ti6Al4V, a popular material used to create screws and other specific materials for dental and orthopedic applications. To improve the biocompatibility of this material, we are creating a suitable glass coating and protocol applicable to the material that meets the thermal characteristics of the metal when sintered, and the biological characteristics suitable to perform exceptionally in the bodily environment. In the past, it has been difficult to develop an appropriate bioactive glass composition that can adhere well enough to this particular titanium alloy.
We are studying the effect that B2O3 has on the already developed glass composition, 6P55, in the improvement of its adhesion and biological behavior as a coating for titanium-based implants.
Effect of Manganese on the S53P4 Bioactive Glass Composition
The novel S53P4 bioactive glass, a synthetic bone graft substitute that has known bone-bonding properties including osteoconductivity, ability to facilitate osteostimulation, and bone proliferation around the material. Additionally, this bioactive glass has an intrinsic antibacterial property that sets it apart from other bioactive glasses, making it vital in septic bone defects. Moreover, S53P4 is known to affect the angiogenesis process. This glass composition is one of the most commonly used bioactive glasses used for clinical application to date, apart from the novel Bioglass®. A few clinical applications that the S53P4 bioactive glass has been used for a bone graft material after benign bone tumor resection, as a substitution in autogenous bone grafting for degenerative spondylolisthesis, as a substitution for PMMA in the treatment for osteomyelitis, just to name a few. Reasons that make S53P4 a suitable substitute for these applications are because of its “off-the-shelf” nature, its excellent bone healing capacity, its lower degradation rate than 45S5, and its antibacterial properties which allow for a much more reliable behavior than antibiotics due to its difference in antibiotic mechanism resulting in an increased provenance of antibiotic resistance behavior. Additionally, S53P4 bioactive glass offers a one-step treatment, compared to the gold standard application which offers a two-step treatment, and a more taxing clinical process.
We are investigating the effect of MnO2 on the S53P4 glass composition by substituting CaCO3 in varying concentrations from 0% to 8% total manganese. Manganese is an essential nutrient found naturally in the body that plays a big role in many chemical processes such as the metabolism of amino acids, cholesterol, fat, and carbohydrates. Additionally, manganese when introduced into the body promotes the formation of connective tissues, bones, blood-clotting factors, and sex hormones. With the incorporation of MnO2 into this glass composition, we aim to improve its biological behavior, while either maintaining or even improving its mechanical properties and bioactivity.
Najwa’s Publications:
Blood-Brain Barrier Integrity and Clearance of Amyloid-β from the BBB
https://pubmed.ncbi.nlm.nih.gov/30315550/
Bioactive glass coatings on metallic implants for biomedical applications
https://www.sciencedirect.com/science/article/pii/S2452199X19300465
https://pubmed.ncbi.nlm.nih.gov/31667443/
Bioactive Glasses in Orthopedic Applications
https://link.springer.com/chapter/10.1007/978-3-030-34471-9_21
Incorporation of novel elements in bioactive glass compositions to enhance implant performance
https://www.intechopen.com/online-first/77966
References:
Baino, Francesco, Sepideh Hamzehlou, and Saeid Kargozar. 2018. “Bioactive Glasses: Where Are We and Where Are We Going?” Journal of Functional Biomaterials 9(1).
Fiume, Elisa, Jacopo Barberi, Enrica Verné, and Francesco Baino. 2018. “Bioactive Glasses: From Parent 45S5 Composition to Scaffold-Assisted Tissue-Healing Therapies.” Journal of Functional Biomaterials 9(1).
Van Gestel, N. A. P., J. Geurts, D. J. W. Hulsen, B. Van Rietbergen, S. Hofmann, and J. J. Arts. 2015. “Clinical Applications of S53P4 Bioactive Glass in Bone Healing and Osteomyelitic Treatment: A Literature Review.” BioMed Research International 2015.
Krishnan, Vidya and T. Lakshmi. 2013. “Bioglass: A Novel Biocompatible Innovation.” Journal of Advanced Pharmaceutical Technology & Research 4(2):78.