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International Journal of Bioprinting Osteogenic, antibacterial CpTi-MgOCu implants

National Ambulatory Medical Care survey, 70% of patients 4.2. Antibacterial performance due to Cu addition
visiting clinics for orthopedic surgery-related issues in Copper was used as a sterilizing agent for chest wounds,
2015–2016 were over 45 years of age . Age has a significant as recorded in Egyptian medical texts dating back
[57]
impact on the quality of recovery, as the quality of bone and 5000 years ago [64] . After it has been used for medical
its healing ability significantly decrease with age . Elderly purposes in the generations that follow, the antibacterial
[58]
patients, who often suffer from immunocompromised potential of copper was discovered in the 19th
bone health, usually have a prolonged recovery after century [65] . In 2011, copper was the first antimicrobial
surgery, which compromises their overall health. The metallic material approved by the U.S. Environmental
infections at the implant site requiring revision surgery Protection Agency (EPA) [65] . Amid the COVID-19
have a huge impact on the health of patients, particularly pandemic, in 2021, U.S. EPA approved the use of
the individuals with age-related decline of bone health, copper-based disinfectants owing to the performance
leading to a further reduction in life expectancy. There is of copper and copper alloys against SARS-CoV-2, i.e.,
an unmet need in metallic implants for materials that can the virus responsible for COVID-19 [66] . Realizing the
provide faster bone remodeling performance and infection potential of Cu as an antibacterial agent, extensive
prevention capabilities beyond what titanium currently research has been conducted on incorporating Cu
offers. Current strategies include cemented implants with into Ti. Cu is a necessary trace element in the human
Ti6Al4V as the bulk material for strength with a surface body in a wide variety of tissues, but higher amounts
coating of bioactive calcium phosphate or hydroxyapatite. of Cu can cause cytotoxicity leading to liver cirrhosis
Despite the superior in vivo performance toward early- and neurologic abnormalities [67] . A debate persists on
stage osseointegration, one of the major shortcomings the optimum amount of Cu in Ti [68-71] . In this study,
of cemented implants is delamination of the calcium with 3 wt.% addition of Cu in CpTi, the H&E-stained
phosphate coating due to poor metal-ceramic bonding. bone sections show no signs of cytotoxicity. However,
Instead, porous titanium metallic coating is a popular the mineralized bone formation in CpTi-MgO-Cu was
choice as it can abate the risk of coating failures . In order observed to be lower than that in CpTi-MgO. Although
[7]
to induce osteogenic properties in these porous titanium 3 wt.% Cu did not cause cytotoxicity, there was a delayed
coatings, MgO addition in CpTi can potentially solve the early-stage osseointegration performance. CpTi-MgO-
coating failure issue. Cu still showed 3.5× mineralized bone formation at
the interface than CpTi, showing superior osteogenic
4.1. Osteogenesis due to MgO addition performance.
Mg plays an essential role in promoting bone calcification
and remodeling. Mg deficiency in the bone has Early-stage osseointegration greatly affects the patient’s
been linked with degenerative bone diseases such as recovery time. With CpTi-MgO-Cu used as a metallic
osteoporosis [59,60] . Mg regulates intracellular calcium ion coating on bulk Ti6Al4V alloy at load-bearing sites,
concentration, pH, transporters, enzymes, and protein coating failures in cemented implants can be avoided. At
synthesis [25,61] . Biodegradable Mg implants for low- the same time, enhanced early-stage osseointegration can
load bearing bone–graft applications have been studied be achieved owing to the osteogenic properties of MgO,
extensively [62,63] . Moreover, incorporating MgO in calcium and inhibition of bacterial infections at the surgery site can
phosphate has enhanced cellular proliferation in vitro prevent revision surgeries.
and osteogenic performance in vivo [8,59] . In this study,
incorporating MgO in CpTi enhanced osteogenesis at the 5. Conclusion
bone–implant interface. With just 1 wt.% MgO addition Early-stage osseointegration at the implant surface is
in CpTi, mineralized bone formation at the BIC increased critical in the post-surgery healing of elderly patients
four-fold compared to that in CpTi (Figure 3c). Bone with degraded bone health. Bio-inertness and non-
remodeling at the implant surface follows osteoblast antibacterial nature of Ti result in aseptic loosening, which
recruitment followed by osteoid lining and eventual necessitates surgical intervention. Without adequate
maturation of bone. CpTi histology images show an material intervention to enhance tissue integration and
osteoid lining at the bone–implant interface. For CpTi- prevent polymicrobial infections, revision procedures
MgO, histology images show mineralized bone directly would further degrade the patient’s health and constitute
apposed to the implant’s outer surface, indicating an a potential risk of morbidity. Ti6Al4V bulk implants
enhanced bone remodeling process compared to CpTi. coated with bioactive ceramics, such as osteogenic MgO
With superior osseointegration performance, we believe and antibacterial Cu, tend to cause coating failures due
CpTi-MgO can potentially replace ceramic coatings in to their weak metal-ceramic bonding. In this study, we
cemented implants and prevent coating failures. propose the addition of 1 wt.% MgO and 3 wt.% Cu to

Volume 9 Issue 6 (2023) 561 https://doi.org/10.36922/ijb.1167