In the field of tissue engineering, there are several issues to consider when designing biomaterials for implants, including cellular interaction, good biocompatibility, and biochemical activity. Biomimetic mineralization has gained considerable attention as an emerging approach for the synthesis of biocompatible materials with complex shapes, categorized organization, controlled shape, and size in aqueous environments. Understanding biomineralization strategies could enhance opportunities for novel biomimetic mineralization approaches. In this regard, mussel-inspired biomaterials have recently attracted many researchers due to appealing features, such as strong adhesive properties on moist surfaces, improved cell adhesion, and immobilization of bioactive molecules via catechol chemistry. This molecular designed approach has been a key point in combining new functionalities into accessible biomaterials for biomedical applications. Polydopamine (PDA) has emerged as a promising material for biomaterial functionalization, considering its simple molecular structure, independence of target materials, cell interactions for adhesion, and robust reactivity for resulting functionalization. In this review, we highlight the strategies for using PDA to induce the biomineralization of hydroxyapatite (HA) on the surface of various implant materials with good mechanical strength and corrosion resistance. We also discuss the interactions between the PDA-HA coating, and several cell types that are intricate in many biomedical applications, involving bone defect repair, bone regeneration, cell attachment, and antibacterial activity.

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In recent decades, the use of plants as a natural remedy has been widely applied in traditional medicine and the treatment of various diseases, including cancer. However, in order to confirm the potential benefits of anticancer drug development from natural sources, in-depth screening assessments are necessary. In the present study, we aimed to evaluate the cytotoxic effects of eight medicinal plants against breast carcinoma and hepatocellular carcinoma cell lines. Remarkably, among all the tested plant extracts, Pyracantha angustifolia and Paullinia cupana extracts showed maximum inhibition in the two cancer cell line models, as detected by cell viability assays, but not in normal mammary epithelial cells. Moreover, induction of cell cycle arrest was seen in both cancer cell models after treatment with extracts derived from the fruits of P. angustifolia and the seeds of P. cupana. Phytochemical and antioxidant analyses demonstrated the presence of high phenolic and flavonoid contents, including an increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity. The growth inhibition of human breast carcinoma and hepatocellular carcinoma cells mediated by both extracts appears to be associated with apoptosis and upregulated expression of pro-apoptotic genes (caspase-3, caspase-7, tumor suppressor protein-p53, cytochrome c, poly (ADP-ribose) polymerase, p53 upregulated modulator of apoptosis, and Bcl-2-associated X-protein). Together, these results indicate that P. angustifolia and P. cupana offer a promising approach for the development of anticancer agents. However, further detailed research is required to make these plants applicable for therapeutic use.

Microneedles (MNs) are a new system of effective drug delivery that create micron-sized pathways to the epidermis or upper dermis regions of the skin. In this study, we developed coated-type microneedles for direct hispidin delivery to the skin. Hispidin is a well-known plant-derived antioxidant component showing antitumor, anti-inflammatory, antiallergic, antiangiogenic, antioxidant, hypoglycemic, hypolipidemic, and immunomodulatory activities. Polymeric blends of polylactic acid (PLA) and polycaprolactone (PCL) were casted as MNs to enhance skin permeability. PLA/PCL MNs exhibited the highest strength of 51.26 MPa with a width of ~200 ųm. Hispidin was directly coated onto the MNs with PLA/PCL blends to form delivery layers. Compared to the hispidin-only delivery layer, skin permeability of hispidin increased by over 50% when using agarose gel in in vitro tests. In a dose-dependent manner, hispidin coated on PLA/PCL MNs also showed a brightening effect, as well as anti-inflammatory activity at the gene and protein level in skin cell culture experiments. It also demonstrated antimicrobial activity, and showed no cytotoxicity to skin cells. These results suggest that the PLA/PCL MN system with hispidin may have great potential as a prototype platform for various drug delivery systems, allowing the development of more effective subcutaneous delivery of vaccines, oligonucleotides, insulin, and many other cosmetic applications.