Considering the role of magnesium in bone metabolism and the increasing relevance of plant-mediated green-synthesis, this work compares the bone cytocompatibility of magnesium hydroxide nanoparticles (NPs) produced by using pure water, Mg(OH)₂, or a rosehip (RH) aqueous extract, Mg(OH)₂RH. The NPs were evaluated for dose- and time-dependent effects on human osteoblastic and osteoclastic response, due to the direct involvement of the two cell types in bone metabolism. Mg(OH)₂ NPs presented nanoplatelet-like morphology (mean diameter ~90 nm) and a crystalline structure (XRD analysis); the RH-mediated synthesis yielded smaller rounded particles (mean diameter <10 nm) with decreased crystallinity. On the ATR–FTIR spectra, both NPs presented the characteristic Mg-OH peaks; Mg(OH)₂RH exhibited additional vibration bands associated with the presence of phytochemicals. On osteoblastic cells, NPs did not affect cell growth and morphology but significantly increased alkaline phosphatase (ALP) activity; on osteoclastic cells, particles had little effect in protein content, tartrate-resistant acid phosphatase (TRAP) activity, percentage of multinucleated cells, and cell area. However, compared with Mg(OH)₂, Mg(OH)₂RH increased osteoblastic differentiation by inducing ALP activity and promoting the expression of Runx2, SP7, Col1a1, and ALP, and had a negative effect on the expression of the osteoclastic genes NFATC1, CA2, and CTSK. These observations suggest the potential usefulness of Mg(OH)₂RH NPs in bone regeneration.

Periodontal disease in dogs leads to progressive bone loss and adversely impacts overall health. However, cost-effective regenerative strategies are still limited in veterinary practice. This study aimed to develop and evaluate a novel tannic acid (TA)–gelatin-based hydrogel (Gel), incorporating graphene oxide (GO) and hydroxyapatite nanoparticles (HA), as a potential barrier material for guided tissue regeneration (GTR) applications. The hydrogels—Gel, Gel-GO, Gel-HA, and Gel-GO-HA—were characterized for chemical structure, molecular interactions, surface morphology, nanoparticle dispersion, and tensile strength. Cytotoxicity was assessed using L929 fibroblasts (ISO 10993-5), while cell viability/proliferation, morphology, and alkaline phosphatase (ALP) production were evaluated using canine periodontal ligament-derived cells. Results show that crosslinking with tannic acid enhanced the incorporation of graphene oxide and hydroxyapatite nanoparticles via hydrogen bonding into TA–gelatin-based hydrogels. This combination increased surface roughness, reduced degradation rate, and enabled shape memory behavior, critical for guided tissue regeneration (GTR) membranes. The extracts from Gel-HA-GO showed that cytotoxicity was both time- and concentration-dependent in L929 fibroblasts, whereas enhanced cell proliferation and increased ALP production were observed in cultures derived from canine periodontal ligament cells. These findings suggest that TA–gelatin-based hydrogels incorporating GO and HA demonstrated favorable mechanical and physicochemical properties, biocompatibility, and osteogenic potential. These attributes suggest their viability as a promising composite for the development of innovative GTR strategies to address periodontal tissue loss in veterinary medicine.

In this work, magnesium hydroxide NPs were synthesized using water (Mg(OH)₂ NPs) or a rose hip (RH) extract (Mg(OH)₂RH NPs) and tested for the bone cells’ effects in co-cultured osteoblastic and osteoclastic cells, using a Transwell^® insert system, allowing reciprocal cell paracrine interactions. Behavior of each cell population was characterized for typical phenotype markers, at days 1 and 6. Cell cultures treated with osteogenic/osteoclastogenic inducers were used as positive control of cell differentiation. The NPs presented a round shape morphology with an average diameter ~90 nm (Mg(OH)₂ NPs) and below 10 nm (Mg(OH)₂RH NPs. Both NPs induced osteoblastic and osteoclastic behavior similarly to that observed in induced osteoblastic and osteoclastic cultures (positive controls). Differences between the two types of particles were evident at the gene expression level. Compared to Mg(OH)₂ NPs, the green-synthesized NPs greatly increased the expression of osteoblastic genes coding for the early markers ALP and collagen type 1 and the later transcription factor osterix, while decreasing the expression of osteoclastogenic genes, namely the essential transcription factor NFATC1, TRAP and the genes coding for the functional markers CA2 and CTSK. Overall, a positive added effect could be hypothesized for Mg(OH)₂RH NPs with potential usefulness to promote bone formation in regenerative applications.

Canine periodontal disease, a progressive and irreversible condition, impacts dental health, posing a significant challenge in veterinary medicine. While current treatments focus on managing progression, canine periodontal ligament stem cells (cPDLSCs) offer regenerative potential through their self-renewal capacity, expression of stemness markers and multilineage differentiation. Autologous cPDLSCs have successfully regenerated alveolar bone, cementum, and Sharpey's fibres, while allogeneic cell transplants have demonstrated immunomodulatory benefits without triggering inflammatory reactions. cPDLSCs also show potential for mitigating inflammation and promoting regeneration in experimentally induced canine periodontal disease. Despite promising preclinical results, challenges such as limited clinical studies, disease variability, high costs, and low owner awareness hinder progress in the use of cPDLSCs in veterinary dental clinical settings. Advancing clinical veterinary science requires conducting clinical trials involving dogs with naturally occurring periodontal disease. Interdisciplinary collaboration can lower costs and expand access to these studies. Additionally, educating pet owners about hygiene practices, early disease detection, and the advantages of regenerative therapies will increase their compliance and improve the outcomes. Ultimately, bridging the gap between research and clinical application through real-world studies is essential for advancing accessible and effective periodontal therapies for dogs. Our review aims to explore the potential of cPDLSCs in both in vitro and in vivo contexts, advancing knowledge of the periodontal microenvironment and paving the way for innovative regenerative therapies.

Periodontal disease affects about 80% of dogs, highlighting the importance of addressing periodontitis in veterinary dental care. The periodontal ligament (PDL) is a key structure holding the potential to regenerate the entire periodontal complex. This work presents an in vitro model of canine PDL-derived cell cultures that mimic the PDL’s regenerative capacity for both mineralised and soft tissues. Explant outgrowth-derived PDL cells were cultured under standard conditions in osteoinductive medium and with hydroxyapatite nanoparticles (Hap NPs). Cell behaviour was assessed for viability/proliferation, morphology, growth patterns, and the expression of osteogenic and periodontal markers. Osteogenic conditions, either achieved with osteoinducers or an osteoconductive biomaterial, strongly promoted PDL-derived cells’ commitment towards the osteogenic phenotype and significantly increased the expression of periodontal markers. These findings suggest that cultured PDL cells replicate the biological function of the PDL, supporting the regeneration of both soft and hard periodontal tissues under normal and demanding healing conditions. This in vitro model will offer a platform for testing new regenerative treatments and materials, ultimately contributing to canine dental care and better outcomes.

Guided bone regeneration (GBR) is a widely used clinical approach for managing bone defects associated with periodontal disease in dogs, employing barrier membranes to selectively direct tissue regeneration. The performance of these membranes is influenced by composition, structural design, and degradation behavior, which together determine biological responses and clinical outcomes. Biodegradable GBR membranes, fabricated from natural polymers, synthetic polymers, or composite materials, offer advantages over non-biodegradable membranes, including controlled resorption, elimination of secondary surgery, and the potential for delivery of bioactive agents. Preclinical studies in dogs have demonstrated that GBR membranes can promote periodontal regeneration, including bone and cementum formation and space maintenance; however, optimization of degradation behavior remains critical to align membrane resorption with tissue healing in some cases. Clinical studies in dogs with naturally occurring periodontal disease remain scarce, and only two biodegradable membranes (Ossiflex^® and Doxirobe^®) are commercially approved for veterinary use, while all others are applied off-label. These limitations highlight the need for more adaptable and cost-effective regenerative strategies, including membranes that can be customized to different defect sizes and multifunctional membranes incorporating bioactive agents that will offer an advanced regenerative potential and improved predictability in veterinary periodontal therapy.