Honey, propolis or royal jelly are considered natural remedies with therapeutic properties since antiquity. Many papers explore the development of antimicrobial biomaterials based on individual bee products, but there is a lack of studies on their synergistic effects. Combining honey, propolis and royal jelly with silver nanoparticles in a biopolymer matrix offers a synergistic strategy to combat antibiotic-resistant bacterial infections. This approach supports progress in wound healing, soft tissue engineering and other domains where elimination of the microorganisms is needed like food packaging. In this study we have obtained antimicrobial films based on bee products and silver nanoparticles (AgNPs) incorporated in an alginate–chitosan blend. The novel biomaterials were analyzed by UV-Vis, fluorescence and FTIR spectroscopy or microscopy, SEM and thermal analysis. Antibacterial tests were conducted against both Gram-positive and Gram-negative bacteria, while the antifungal properties were tested against Candida albicans. The diameters for growth inhibition zones were up to 10 mm for bacterial strains and 8 mm for the fungal strain. Additionally, cytotoxicity assays were performed to evaluate the biocompatibility of the materials, the results indicating that the combination of honey, propolis, royal jelly and AgNPs does not produce synergistic toxicity.

In the latter part of the 20th century, remarkable developments in new dental materials and technologies were achieved. However, regarding the impact of dental resin-based materials 3D-printed on cellular responses, there have been a limited number of published studies recently. The biocompatibility of dental restorative materials is a controversial topic, especially when discussing modern manufacturing technologies. Three-dimensional printing generates the release of residual monomers due to incomplete polymerization of materials and involves the use of potentially toxic substances in post-printing processes that cannot be completely eliminated. Considering the issue of biocompatibility, this article aims to establish an overview of this aspect, summarizing the different types of biocompatibility tests performed on materials used in 3D printing in dentistry. In order to create this comprehensive review, articles dealing with the issue of 3D printing in dentistry were analysed by accessing the main specialized search engines using specific keywords. Relevant data referring to types of materials used in 3DP to manufacture various dental devices, polymerization methods, factors affecting monomer release, cytotoxicity of unreacted products or post-curing treatments, and methods for assessing biocompatibility were analysed. Although the introduction of new restorative materials used in dental treatments is subject to national and international regulations and standards, it is necessary to investigate them regarding biocompatibility in order to support or deny the manufacturers’ statements regarding this aspect.

The increasing prevalence of antibiotic-resistant bacteria has stimulated the search for alternative antimicrobial agents with greater efficacy, low toxicity, and minimal resistance potential. Natural products, such as honey, propolis, and royal jelly, have shown promise due to their biological properties. The integration of natural products like honey and propolis in biomaterials represents a synergistic approach to combat the growing threat of resistant bacterial infections while improving wound care and soft tissue engineering applications. In the present work, we obtained sodium alginate films based on honey, propolis, royal jelly, and their mixture coated with chitosan for soft tissue regeneration. SEM showed that adding bee products altered surface morphology, affecting roughness, porosity, and microstructure. Spectral analysis confirmed specific chemical bonds, while thermal studies indicated a good stability up to 115 °C. The antimicrobial activity was evaluated against Gram-positive (Enterococcus faecalis, Staphylococcus aureus), Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and yeast strains (Candida albicans), with growth inhibition zone diameters up to 12 mm. In vitro cytotoxicity studies, made on human gingival fibroblasts, suggested good biocompatibility. Antimicrobial assays showed that films containing propolis tincture, alone or as a mixture, were most effective against pathogens. Future research will focus on formulation optimization for biomedical use.

Computer-aided design and computer-aided manufacturing (CAD/CAM) techniques are based on either subtractive (milling prefabricated blocks) or additive (3D printing) methods, and both are used for obtaining dentistry materials. Our in vitro study aimed to investigate the behavior of human gingival fibroblasts exposed to methacrylate (MA)-based CAD/CAM milled samples in comparison with that of MA-based 3D-printed samples to better elucidate the mechanisms of cell adaptability and survival. The proliferation of human gingival fibroblasts was measured after 2 and 24 h of incubation in the presence of these samples using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the membrane integrity was assessed through the lactate dehydrogenase release. The level of reactive oxygen species, expression of autophagy-related protein LC3B-I, and detection of GSH and caspase 3/7 were evaluated by fluorescence staining. The MMP-2 levels were measured using a Milliplex MAP kit. The incubation with MA-based 3D-printed samples significantly reduced the viability, by 16% and 28% from control after 2 and 24 h, respectively. There was a 25% and 55% decrease in the GSH level from control after 24 h of incubation with the CAD/CAM milled and 3D-printed samples, respectively. In addition, higher levels of LC3B-I and MMP-2 were obtained after 24 h of incubation with the MA-based 3D samples compared to the CAD/CAM milled ones. Therefore, our results outline that the MA-CAD/CAM milled samples displayed good biocompatibility during 24-h exposure, while MA-3D resins are proper for short-term utilization (less than 24 h).

Curcumin is a polyphenol of the Curcuma longa plant, which can be used for various medicinal purposes, such as inflammation and cancer treatment. In this context, two symmetric curcumin derivatives (D1—(1E,6E)-1,7-bis(4-acetamidophenyl)hepta-1,6-diene-3,5-dione and D2—p,p-dihydroxy di-cinnamoyl methane) were obtained by the microwave-based method and evaluated for their antitumoral effect on human cervix cancer in comparison with toxicity on non-tumoral cells, taking into account that they were predicted to act as apoptosis agonists or anti-inflammatory agents. The HeLa cell line was incubated for 24 and 72 h with a concentration of 50 μg/mL of derivatives that killed almost half of the cells compared to the control. In contrast, these compounds did not alter the viability of MRC-5 non-tumoral lung fibroblasts until 72 h of incubation. The nitric oxide level released by HeLa cells was higher compared to MRC-5 fibroblasts after the incubation with 100 μg/mL. Both derivatives induced the decrease of catalase activity and glutathione levels in cancer cells without targeting the same effect in non-tumoral cells. Furthermore, the Western blot showed an increased protein expression of HSP70 and a decreased expression of HSP60 and MCM2 in cells incubated with D2 compared to control cells. We noticed differences regarding the intensity of cell death between the tested derivatives, suggesting that the modified structure after synthesis can modulate their function, the most prominent effect being observed for sample D2. In conclusion, the outcomes of our in vitro study revealed that these microwave-engineered curcumin derivatives targeted tumor cells, much more specifically, inducing their death.

In clinical practice, the selection of dental material is a crucial factor for the final success of the treatment, regarding mechanical properties and biocompatibility. Our study aimed to evaluate the cytotoxicity of a PMMA dental resin used for denture base fabrication and to investigate whether autophagy might be involved in the response of the exposed cells. In vitro tests, such as assessments of cell viability and metabolism, nitric oxide (NO), lactate dehydrogenase (LDH), and autophagy, were conducted. The results showed that exposure to PMMA-based material decreased cell viability by 35% after 24 h and 36% after 48 h. NO levels increased by 10% after 24 h and 2% after 48 h. LDH levels increased by 8% after 24 h and 31% after 48 h. Within the limits of this present study, our results suggest a significant activation of autophagy in the exposed fibroblasts, possibly as a survival mechanism, based on the viability and cell metabolic activity results.