This study evaluated the biological performance in vitro of two 3D-printed hydroxyapatite (HA) and polylactic acid (PLA) composite scaffolds with two different infill densities (50% [HA-PLA50] and 70% [HA-PLA70]). Comparative analysis using MG-63 cell cultures evaluated the following: (1) integrity after exposure to various sterilization methods; (2) cell viability; (3) morphological characteristics; (4) cell proliferation; (5) cytotoxicity; (6) gene expression; and (7) protein synthesis. Ultraviolet radiation was the preferred sterilization method. Both scaffolds maintained adequate cell viability and proliferation over 7 days without significant differences in cytotoxicity. Notably, HA-PLA50 scaffolds demonstrated superior osteogenic potential, showing a significantly higher expression of collagen type I (COL1A1) and an increased synthesis of interleukins 6 and 8 (IL-6, IL-8) compared to HA-PLA70 scaffolds. While both scaffold types supported robust cell growth, the HA-PLA50 formulation exhibited enhanced bioactivity, suggesting a potential advantage for bone tissue engineering applications. These findings provide important insights for optimizing 3D-printed bone graft substitutes.

This study characterized the biological response of MG-63 cells to synthetic, hydroxyapatite scaffolds (HAsint) fabricated via fused filament fabrication. Scaffolds were compared to 2D plate-adherent cultures using six assays: cell morphology and distribution with scanning electron microscopy and confocal laser scanning microscopy; cell proliferation and cytotoxicity via WST-1 tetrazolium assay; relative osteogenic gene expression through reverse-transcription–quantitative polymerase chain reaction, and protein synthesis via multiplex immunoassay. Data were analyzed using one-way ANOVA. Results confirmed high cell viability and uniform distribution on HAsint scaffolds. Proliferation increased significantly over 7 days, though direct cytotoxicity also increased, likely due to the static conditions of the experiment and, subsequently, the high ion reprecipitation from scaffold degradation. Importantly, HAsint scaffolds significantly enhanced osteogenic marker expression of phosphatase alkaline (ALPL), osteopontin (OPN), and osteocalcin (OCN) genes, and elevated concentrations of interleukins (IL)-6, IL-8 and matrix metalloproteinase 1 compared to plate-adherent controls. It can be concluded that 3D-printed HAsint scaffolds support robust osteogenic differentiation and proliferation despite inducing a transient cytotoxic response in vitro. The marked upregulation of key osteogenic genes and proteins confirms the scaffolds’ bioactivity and highlights their potential for bone tissue engineering applications.

Aim: To compare microbiological and immunological parameters of two sandblasted, large‐grit, acid‐etched implant surfaces during the first 8 weeks of healing following implant placement. Materials and Methods: A dual‐center, split‐mouth, randomized controlled clinical trial was conducted on patients receiving one test (modified hydrophilic surface) and one control (conventional surface) implant in different quadrants. Peri‐implant crevicular fluid samples were collected at implant placement and at 1, 2, 4, and 8 weeks to assess biomarkers of inflammation (Interleukin [IL]‐1β, IL‐6, Tumor Necrosis Factor‐α, IL‐2), biomarkers of anti‐inflammation (IL‐4, IL‐10), and biomarkers of bone metabolism (osteocalcin, osteopontin [OPN], and vascular endothelial growth factor‐α [VEGF‐α]). Additionally, submucosal samples were obtained at implant placement and at 1, 2, and 4 weeks and analyzed using quantitative polymerase chain reaction (qPCR) and 16S rRNA sequencing. Biomarkers and qPCR data were analyzed with a general linear model using log10‐transformed values. Microbiome data were analyzed via Wilcoxon tests and PERMANOVA. Results: Sixty patients were included in the 8‐week analysis. VEGF‐α levels were significantly higher at 1 week for the conventional surface ( p = 0.018). OPN and IL‐10 significantly increased from baseline to 4 weeks in both groups. Porphyromonas gingivalis and Fusobacterium species were the most prevalent bacteria; however, no significant differences were found between the surfaces in bacterial load analysis by qPCR. Additionally, no significant differences were observed between groups for microbiome diversity. Conclusion: No differences were detected between the conventional and the modified hydrophilic surfaces in the immunological and microbiological parameters assessed during early implant healing.

This study aimed to characterize the transcriptional response of Porphyromonas gingivalis biofilms to treatment with xanthohumol and curcumin. A validated dynamic in vitro biofilm model, based on microbial growth under flow and shear conditions resembling the oral cavity, was used to develop mature biofilms of P. gingivalis on sterile ceramic calcium hydroxyapatite discs. Transcriptional profiles of biofilms, treated and untreated with both extracts, were obtained through RNA-Sequencing (RNA-Seq). The biofilm development and the lack of phenotypic effects from sublethal concentrations of xanthohumol and curcumin were confirmed via Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Reverse transcription quantitative PCR (RT-qPCR) was employed to verify differentially expressed genes identified by RNA-Seq. Xanthohumol and curcumin caused extensive reprogramming of P. gingivalis biofilm gene expression. Out of 1,973 genes, xanthohumol activated 173 and repressed 286, whereas curcumin activated 170 and repressed 163. These changes affected genes involved in membrane integrity, oxidative stress, transmembrane transport, and virulence, suggesting a mechanism of action that involves membrane disruption.