The increasing demand for non-invasive biocompatible materials in biomedical applications, driven by accidents and diseases like cancer, has led to the development of sustainable biomaterials. Here, we report the synthesis of four block formulations using polycaprolactone (PCL), polylactic acid (PLA), and zinc oxide nanoparticles (ZnO-NPs) for subdermal tissue regeneration. Characterization by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) confirmed the composition of the composites. Additionally, the interaction of ZnO-NPs mainly occurred with the C=O groups of PCL occurring at 1724 cm⁻¹, which disappears for F4, as evidenced in the FT-IR analysis. Likewise, this interaction evidenced the decrease in the crystallinity of the composites as they act as crosslinking points between the polymer backbones, inducing gaps between them and weakening the strength of the intermolecular bonds. Thermogravimetric (TGA) and differential scanning calorimetry (DSC) analyses confirmed that the ZnO-NPs bind to the carbonyl groups of the polymer, acting as weak points in the polymer backbone from where the different fragmentations occur. Scanning electron microscopy (SEM) showed that the increase in ZnO-NPs facilitated a more compact surface due to the excellent dispersion and homogeneous accumulation between the polymeric chains, facilitating this morphology. The in vivo studies using the nanocomposites demonstrated the degradation/resorption of the blocks in a ZnO-NP-dependant mode. After degradation, collagen fibers (Type I), blood vessels, and inflammatory cells continue the resorption of the implanted material. The results reported here demonstrate the relevance and potential impact of the ZnO-NP-based scaffolds in soft tissue regeneration.

Tissue accidents provide numerous pathways for pathogens to invade and flourish, causing additional harm to the host tissue while impeding its natural healing and regeneration. Essential oils (EOs) exhibit rapid and effective antimicrobial properties without promoting bacterial resistance. Clove oils (CEO) demonstrate robust antimicrobial activity against different pathogens. Chitosan (CS) is a natural, partially deacetylated polyamine widely recognized for its vast antimicrobial capacity. In this study, we present the synthesis of four membrane formulations utilizing CS, polyvinyl alcohol (PVA), and glycerol (Gly) incorporated with CEO and nanobioglass (n-BGs) for applications in subdermal tissue regeneration. Our analysis of the membranes’ thermal stability and chemical composition provided strong evidence for successfully blending polymers with the entrapment of the essential oil. The incorporation of the CEO in the composite was evidenced by the increase in the intensity of the band of C-O-C in the FTIR; furthermore, the increase in diffraction peaks, as well as the broadening, provide evidence that the introduction of CEO perturbed the crystal structure. The morphological examination conducted using scanning electron microscopy (SEM) revealed that the incorporation of CEO resulted in smooth surfaces, in contrast to the porous morphologies observed with the n-BGs. A histological examination of the implanted membranes demonstrated their biocompatibility and biodegradability, particularly after a 60-day implantation period. The degradation process of more extensive membranes involved connective tissue composed of type III collagen fibers, blood vessels, and inflammatory cells, which supported the reabsorption of the composite membranes, evidencing the material’s biocompatibility.

After tooth extraction, bone levels in the alveoli decrease. Using a bone substitute can help minimize this bone loss. The substitute can be sourced from a human or animal donor or synthetically prepared. In this study, we aimed to address the following PICOS question: In patients needing dental alveolar preservation for implant placement, how does alveolar preservation using a bovine hydroxyapatite bone xenograft with collagen compare to a xenograft without collagen in terms of changes in alveolar height and width, bone density, and the characteristics of the bone tissue observed in biopsies taken at 6 months? We evaluated two xenograft-type bone substitutes for preserving post-extraction dental sockets using tomography and microscopy to answer that question. A total of 18 dental alveoli were studied: 11 preserved with a xenograft composed of apatite (InterOss) and 7 with a xenograft composed of apatite–collagen (InterOss Collagen). Tomographic controls were performed at 1 and 6 months, and microscopic studies were performed on 13 samples. The biopsies were examined with scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). A Multivariate Analysis of Variance (MANOVA) was conducted in the statistical analysis, revealing a significant increase in bone density over time (p = 0.04). Specifically, bone density increased from an average of 526.14 HU at 30 days to 721.96 HU at 60 days in collagen-free samples. However, no statistically significant differences in height or width were found between groups. The MANOVA results indicated that the overall model had a low predictive ability for height, width, and density variables (R-squared values were low), likely due to sample size limitations and the complexity of bone tissue dynamics. On the other hand, FTIR analysis revealed the presence of phosphate groups, carbonates, and amides I, II, and III, indicative of inorganic (hydroxyapatite) and organic (type I collagen) materials in the xenografts. TGA and DSC showed high thermal stability, with minimal mass loss below 150 °C. Finally, both xenografts were influential in alveolar bone regeneration after extraction without significant differences. The trend of increasing collagen density suggests an effect that requires further investigation. However, it is recommended that the sample size be increased to enhance the validity of the results.

In the original publication [...].

Graphene oxide (GO) offers a high-surface-area platform for the noncovalent association of hydrophobic bioactive compounds, but its biological response depends strongly on surface chemistry. Here, GO was carboxylated with sodium chloroacetate and physically associated with curcumin (CUR) to obtain a graphene oxide–curcumin nanoadduct (GO-COOH-CUR). Ultraviolet-visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to assess chemical and morphological changes. XPS showed a lower C/O ratio and a higher fitted O-C=O contribution after carboxylation, although residual Na and Cl were detected. UV-vis, FTIR and XPS features were consistent with the presence of curcumin in the formulation with 83.35% of encapsulation efficiency (EE). In 24 h MTT assays, CO-COOH-CUR maintained BHK-21 metabolic activity above 70% across 3.125 µg mL⁻¹ and reduced MCF-7 metabolic activity at the higher tested concentrations. Because formulation concentrations were expressed as a total mass and curcumin concentration is not reported here, direct potency or selectivity comparisons with free curcumin were not made. Qualitative histological evaluation performed 30 days after subdermal implantation in three male Wistar rats showed preserved adjacent tissue architecture, with no evident necrosis, prominent inflammatory infiltrate, organized fibrous capsule, or foreign-body giant cell response in the sections evaluated. These findings support further evaluation of GO-COOH-CUR within the limits of MTT-based and qualitative assessment.

In this study, three formulations (F1, F2, and F3) were developed to fabricate hybrid scaffolds composed of chitosan (CS), polyvinylpyrrolidone (PVP), and polyvinyl alcohol (PVA), doped with curcumin (CUR) and silicon dioxide nanoparticles (NPs-SiO₂). Structural analysis of the scaffolds was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). This analysis demonstrated that incorporating bioactive molecules, such as curcumin (CUR) and silicon dioxide nanoparticles (NPs-SiO₂), modified intermolecular interactions within the prepared scaffolds, thereby favoring the formation of more stable amorphous structures. This effect was most evident in scaffold formulation 3, which exhibited a more porous architecture with a uniform distribution of NPs-SiO₂. Furthermore, mechanical evaluation of the formulations revealed that F2 exhibited the highest elastic modulus (0.773 ± 0.177 MPa) and compressive strength (1.015 ± 0.012 MPa), while F3 showed a more balanced combination of flexibility, structural stability, and displacement capacity. All formulations achieved complete inhibition of the Gram-positive and Gram-negative bacterial strains evaluated under the same test conditions. In vitro studies demonstrated that F3 maintained cell viability above 80% in normal BHK-21 fibroblasts while exhibiting enhanced cytotoxicity toward HEp-2 tumor cells (IC₅₀ = 373.6 µg/mL). Additionally, subdermal implantation revealed the presence of trabeculae-like structures, osteocyte-like lacunae, and osteoblastic-like cells in F3, suggesting the initiation of osteogenic-type tissue organization. These findings identify F3 as the formulation with the most favorable balance of structural, mechanical, antimicrobial, and biological properties, supporting its potential application as a multifunctional scaffold for tissue regeneration.