## 1 Introduction
Low SiO\({}_{2}\) is a well-recognized characteristic of bioactive glasses that facilitates degradation in a hydrated environment [36]. Zn\({}^{2+}\) can impart positive therapeutic effects on bone metabolism [37; 38], while Ca\({}^{2+}\) is interchangeable within mineralized tissues, thereby facilitating bone bonding properties. However, there exists a hierarchy when incorporating ions within a GPC, and Al\({}^{3+}\) is known to form the strongest bond during the setting reaction (M = Al\({}^{3+}\) > Cu\({}^{2+}\) > Zn\({}^{2+}\) > Ca\({}^{2+}\) > Mg\({}^{2+}\)) [4]. Divalent cations can link two polyanionic chains together, thereby forming a bond with a high ionic strength. These bonds form as the materials cure and are responsible for their unique physical and mechanical properties [10]. The availability of the unbound ions facilitates ion release and the biological properties associated with these materials. The focus of this study was to elucidate the bioactive properties of gallium (Ga\({}^{3+}\)) when incorporated within a SiO\({}_{2}\)-ZnO-CaO glass phase prior to forming a series of Ga-glass polyalkenoate cements (Ga-GPCs). Ga was incorporated at 0.08 and 0.16 mol\(\%\) additions at the expense of Zn\({}^{2+}\). Ga\({}^{3+}\) is reported to have numerous beneficial effects in vivo, including antimicrobial properties [39; 40; 41; 42], anti-inflammatory [43], and anti-cancerous effects [44; 45; 46]. Previous work has demonstrated the efficacy of Ga\({}^{3+}\) against opportunistic pathogenic bacteria such as _Pseudomonas aeruginosa (P. aeruginosa)_, which can cause airway infections in cystic fibrosis patients [39; 40; 41; 46], and opportunistic fungi such as _Cryptococcus neoformans_, which can cause life-threatening diseases in immunocompromised patients [47]. [PERSON] et al. investigated the effects of both gallium nitrate and transferrin-gallium on the bacterial species _Mycobacterium tuberculosis_ and _Mycobacterium avium_, discovering that these two gallium compounds acted to inhibit the iron-dependent growth of the bacteria [48]. A study conducted by [PERSON] et al. investigated the effects of gallium nitrate on _P. aeruginosa_ pneumonia in mice. This investigation revealed that the gallium-containing compounds inhibited the growth of _P. aeruginosa_ and also prevented the formation of biofilm. This study also showed that in the case of _P. aeruginosa_, gallium nitrate again interfered with iron uptake, resulting in the death of both planktonic and biofilm bacteria in vitro [41]. Ga\({}^{3+}\) has also been shown to increase bone calcium levels by inhibiting resorption [49; 50; 51]. The mechanism for this activity involves the recruitment of Ga\({}^{3+}\) to bone tissue and the suppression of osteocl differentiation markers (TRAP, CTR, CTK, and RANK) [50]. Metabolic studies with bone cancer patients also support this observation; patients who were given a gallium nitrate supplement showed a decreased concentration of calcium in the urine, suggesting improved mineral retention and utilization [52]. Ga has also been studied for its ability to treat cancer; the absorption of radioactive gallium by malignant cells led to research being conducted by the National Cancer Institute (NCI), in which they investigated the ability of salts of group IIIa metals to inhibit the growth of malignant cells in mice and rats [53]. Out of the various compounds tested, gallium nitrate (Ga(NO\({}_{3}\))\({}_{3}\)) exhibited the ability to suppress the growth of subcutaneously implanted tumors, while also exhibiting the least toxicity of the compounds investigated. Since these abilities of gallium nitrate were discovered, many clinical trials have been conducted in an attempt to identify which forms of cancer this compound is effective against. Gallium nitrate has been proven effective in the treatment of non-Hodgkin lymphoma [54], bladder cancer [55], multiple myeloma [56], and metastatic urothelial carcinoma [57], in addition to being investigated for treating cancer-related hypercalcemia [58; 59].