The zero (0-D) and one-dimensional (1-D) carbon nanomaterials have gained attention among researchers because they exhibit a larger surface area to volume ratio, and a smaller size. Furthermore, carbon is ubiquitously present in all living organisms. However, toxicity is a major concern while utilizing carbon nanomaterials for biomedical applications such as drug delivery, biosensing, and tissue regeneration. In the present review, we have summarized some of the recent findings of cellular and animal level toxicity studies of 0-D (carbon quantum dot, graphene quantum dot, nanodiamond, and carbon black) and 1-D (single-walled and multi-walled carbon nanotubes) carbon nanomaterials. The in vitro toxicity of carbon nanomaterials was exemplified in normal and cancer cell lines including fibroblasts, osteoblasts, macrophages, epithelial and endothelial cells of different sources. Similarly, the in vivo studies were illustrated in several animal species such as rats, mice, zebrafish, planktons and, guinea pigs, at various concentrations, route of administrations and exposure of nanoparticles. In addition, we have described the unique properties and commercial usage, as well as the similarities and differences among the nanoparticles. The aim of the current review is not only to signify the importance of studying the toxicity of 0-D and 1-D carbon nanomaterials, but also to emphasize the perspectives, future challenges and possible directions in the field.

Because of recent research advances in nanoscience and nanotechnology, there has been a growing interest in functional nanomaterials for biomedical applications, such as tissue engineering scaffolds, biosensors, bioimaging agents and drug delivery carriers. Among a great number of promising candidates, graphene and its derivatives—including graphene oxide and reduced graphene oxide—have particularly attracted plenty of attention from researchers as novel nanobiomaterials. Graphene and its derivatives, two-dimensional nanomaterials, have been found to have outstanding biocompatibility and biofunctionality as well as exceptional mechanical strength, electrical conductivity and thermal stability. Therefore, tremendous studies have been devoted to employ functional graphene nanomaterials in biomedical applications. Herein, we focus on the biological potentials of functional graphene nanomaterials and summarize some of major literature concerning the multifaceted biomedical applications of functional graphene nanomaterials to coated substrates, patterned arrays and hybrid scaffolds that have been reported in recent years.

The initial stability of a dental implant is known to be an indicator of osseointegration at immediate loading upon insertion. Implant designs have a fundamental role in the initial stability. Although new designs with advanced surface technology have been suggested for the initial stability of implant systems, verification is not simple because of various assessment factors. Our study focused on comparing the initial stability between two different implant systems via design aspects. A simulated model corresponding to the first molar derived from the mandibular bone was constructed. Biomechanical characteristics between the two models were compared by finite element analysis (FEA). Mechanical testing was also performed to derive the maximum loads for the two implant systems. CMI IS-III active (IS-III) had a more desirable stress distribution than CMI IS-II active (IS-II) in the surrounding bone region. Moreover, IS-III decreased the stress transfer to the nerve under the axial loading direction more than IS-II. Changes of implant design did not affect the maximum load. Our analyses suggest that the optimized design (IS-III), which has a bigger bone volume without loss of initial fixation, may minimize the bone damage during fixture insertion and we expect greater effectiveness in older patients.

A nanofiber-based composite nonwoven fabric was fabricated for hemostatic wound dressing, integrating polyvinyl alcohol (PVA), kaolin, and γ-chitosan extracted from three type of insects. The γ-chitosan extracted from Protaetia brevitarsis seulensis exhibited the highest yield at 21.5%, and demonstrated the highest moisture-binding capacity at 535.6%. In the fabrication process of PVA/kaolin/γ-chitosan nonwoven fabrics, an electrospinning technique with needle-less and mobile spinneret was utilized, producing nanofibers with average diameters ranging from 172 to 277 nm. The PVA/kaolin/γ-chitosan nonwoven fabrics demonstrated enhanced biocompatibility, with cell survival rates under certain compositions reaching up to 86.9% (compared to 74.2% for PVA). Furthermore, the optimized fabric compositions reduced blood coagulation time by approximately 2.5-fold compared to PVA alone, highlighting their efficacy in hemostasis. In other words, the produced PVA/kaolin/γ-chitosan nonwoven fabrics offer potential applications as hemostatic wound dressings with excellent biocompatibility and improved hemostatic performance. Graphical abstract

A polyphenolic extract from melon (Cucumis melo L.), as a potential source of natural antioxidants, has been reported to have a positive effect on osteoblast activity. In this study, the protective effects of heat-treated melon extract (ECO-A) on bone strength, mineralization, and metabolism were examined in osteoporotic rat models. Osteoporosis was induced by ovariectomy (OVX) in female rats and then maintained for 8 weeks, along with the ingestion of phosphate-buffered saline (PBS, OVXP) or ECO-A (OVXE) for an additional 4 weeks. At a pre-determined timepoint, bone strengths, as well as bone mineral contents (BMC) and the density (BMD) of femurs and/or lumbar spines extracted from each animal, were measured by a mechanical test and dual-energy X-ray absorptiometry, respectively. Moreover, several biochemical markers for bone turnover were analyzed by respective colorimetric assay kits in addition to clinical analyses. The maximum load and stiffness of femurs from the OVXE group were found to be significantly higher than the other groups. Furthermore, the OVXE group showed significantly higher BMC, BMD, and bone volume than the OVX and OVXP groups, which were comparable to the non-OVX (sham) group. The levels of bone formation and resorption markers in the OVXE group were similar to the sham group, but significantly different from other groups. In conclusion, these results suggest that ECO-A can play potentially positive roles in the protection of bone loss in rats with OVX-induced osteoporosis.

Synthesis of polycarbonates (PCs) from isosorbide (ISB) monomers has been recently investigated. However, compared to bisphenol A, PCs face challenges in commercialization because their high rigidity renders it difficult to increase their molecular weight, resulting in high brittleness. To address these limitations, a flexible co‐monomer, ethoxylated ISB (EI5), was mixed with ISB to produce ISB/EI5‐based PCs. The structures of the ISB/EI5‐based PCs were controlled by varying the ISB/EI5 ratio from 100/0 to 60/40 mol%. Films were fabricated, and their thermal, optical, and mechanical properties and degradability were investigated. With increasing EI5 content, the thermal processability of the ISB/EI5‐based PCs improved, and the produced films exhibited excellent visible light transmittance and UV‐blocking effects. The mechanical properties of the ISB/EI5‐based PCs indicated sufficient tensile strength (σ = 89.7–72.9 MPa), competitive to that of commercial PC, and the properties could be controlled by adjusting the ISB/EI5 ratio. The contact angle and hydrolysis behavior of the ISB/EI5‐based PC films indicated increased surface hydrophilicity and increased degradation rate with increasing EI5 content. In conclusion, the structural control of the ISB/EI5‐based PCs enhanced their moldability and degradability, suggesting their potential commercial utilization.