The Influence of Basil and Cinnamon Essential Oils on Bioactive Sponge Composites of Collagen Reinforced with Hydroxyapatite

The increasing prevalence of acute traumas, surgical wounds, and chronic skin wounds poses significant therapeutic challenges for wound treatment. One of the main concerns in wound care is the danger of infection, which is a significant barrier to healing and a cause of higher morbidity and mortality rates. The emergence of drug-resistant bacterial species is becoming more frequent every day. Antimicrobial dressings have become a viable strategy for wound healing and hospital expense savings. Several factors, such as the wound's localization and state, microbial load, and cost, must be considered when choosing an appropriate antimicrobial dressing. One of the key goals of wound care is infection avoidance. This study addresses the therapeutic challenges of acute traumas, surgical wounds, and chronic skin wounds, focusing on infection prevention and combating drug-resistant bacterial strains. The research explores the development of novel composite wound dressings incorporating hydroxyapatite, known for its osteoconductive properties, and essential oils from basil and cinnamon, recognized for their antimicrobial activity. The study evaluates the impact of these additives on key properties such as surface morphology, water absorption, enzymatic degradation, and mechanical performance. Antimicrobial tests showed that two experimental samples (A1S and A1BS) exhibited significant activity against Escherichia coli but not on Staphylococcus aureus. The results highlight the dressings' enhanced antimicrobial properties, mechanical strength, and controlled degradation, making them promising candidates for advanced wound healing. Tailored applications were identified, with each dressing composition offering unique benefits for specific wound-healing scenarios based on the balance between flexibility, structural support, and bioactivity.

Synthesis and characterization of mesoporous bioactive glass nanoparticles loaded with peganum harmala for bone tissue engineering

Globally, there is an increase in a number of bone disorders including osteoarthritis (OA), osteomyelitis, bone cancer, and etc., which has led to a demand for bone tissue regeneration. In order to take use of the osteogenic potential of natural herbs, mesoporous bioactive glass nanoparticles (MBGNs) have the ability to deliver therapeutically active chemicals locally. MBGNs influence bioactivity and osteointegration of materials making them suitable for bone tissue engineering (BTE). In the present study, we developed Peganum Harmala (P. harmala) loaded MBGNs (PH-MBGNs) synthesized via modified Stöber process. The MBGNs were analyzed in terms of surface morphology, chemical make-up, amorphous nature, chemical interaction, pore size, and surface area before and after loading with P. harmala. A burst release of drug from PH-MBGNs was observed within 8 h immersion in phosphate buffer saline (PBS). PH-MBGNs effectively prevented Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) from spreading. Furthermore, PH-MBGNs developed a hydroxyapatite (HA) layer in the presence of simulated body fluid (SBF) after 21 days, which confirmed the in-vitro bioactivity of MBGNs. In conclusion, PH-MBGNs synthesized in this work are potential candidate for scaffolding or a constituent in the coatings for BTE applications.

Integrity of the ECM Influences the Bone Regenerative Property of ECM/Dicalcium Phosphate Composite Scaffolds

Due to the limitation of clinical autologous bone supply and other issues, the development of bone regeneration materials is still a hot topic. Natural tissue-derived bone repair materials have good biocompatibility and degradability, but their structure and properties are likely to be adversely affected during terminal sterilization. In this study, a composite scaffold consisting of the acellular extracellular matrix and dicalcium phosphate (ECM/DCP) was fabricated and terminally sterilized by γ-ray irradiation. In addition, the ECM/DCP scaffold was saturated with water and was also sterilized by γ-ray irradiation (RX-ECM/DCP). Results showed that the triple helix structure of collagen was better maintained in RX-ECM/DCP than in ECM/DCP. The thermal stability of RX-DCP/ECM was much better than that of ECP/ECM. The in vitro and in vivo performances of both types of scaffolds were also evaluated. The RX-ECM/DCP scaffold exhibited better in vitro bioactivity than that of the ECM/DCP scaffold as evidenced by more mineral formation in the simulated body fluid. In addition, RX-ECM/DCP also induced more effective bone regeneration than the ECM/DCP scaffold did in a rat calvarial defect model. Results sufficiently demonstrated that the addition of water to the scaffold could protect the structure of the ECM/DCP scaffold from being damaged by γ-ray irradiation during the terminal sterilization process. In summary, this study demonstrated a means to protect the ECM structure, which in turn led to the improvement of bone regenerative properties of the materials during γ-ray irradiation of ECM-based bone repair materials.

Di-tert-butylphosphate Derived Thermolabile Calcium Organophosphates: Precursors for Ca(H2PO4)2, Ca(HPO4), α-/β-Ca(PO3)2, and Nanocrystalline Ca10(PO4)6(OH)2

Thermally and hydrolytically unstable di-tert-butyl phosphate (dtbp-H) has been used as synthon to prepare discrete and polymeric calcium phosphates that are convenient single-source precursors for a range of calcium phosphate ceramic biomaterials. The reactivity of dtbp-H toward two different calcium sources has been found to vary significantly, e.g., the reaction of Ca(OMe)₂ with dtbp-H in a 1:6 molar ratio in petroleum ether forms a mononuclear calcium hexa-phosphate complex [Ca(dtbp)₂(dtbp-H)₄] (1), whereas the change of calcium source to CaH₂, in a 1:2 molar ratio under otherwise similar reaction conditions, yields the calcium phosphate polymer, [Ca(μ-dtbp)₂(H₂O)₂·H₂O]_n(2). Compounds 1 and 2 have been extensively characterized by various spectroscopic and analytical techniques. The solid-state structures of both 1 and 2 have been determined by single-crystal X-ray diffraction studies. In discrete molecule 1, the central calcium ion is surrounded by two anionic dtbp and four neutral dtbp-H ligands in an octahedral coordination environment. Compound 2 is a one-dimensional polymer in which adjacent calcium ions are connected through double dtbp bridges. Solid-state thermolysis of bulk 1 in air leads to the exclusive formation of calcium metaphosphate β-Ca(PO₃)₂ in the entire temperature range of 400-800 °C. Thermal decomposition of polymer 2, however, can be fine-tuned to produce either α-Ca(PO₃)₂ or β-Ca(PO₃)₂ depending on the thermolysis conditions employed. Although the sample sintered at 600 °C produces exclusively α-form of Ca(PO₃)₂, the sample annealed at 800 °C or above produces β-form. Both α- and β-forms can also be successively formed one after other by a slow heating of a freshly prepared 2 on the powder diffractometer sample holder. Additional forms of ceramic phosphates have been prepared by solvothermal conditions because of the highly labile nature of the tert-butoxy groups of dtbp in 1 and 2. Solution decomposition of either 1 or 2 in boiling toluene at 140 °C in a sealed tube produces calcium dihydrogen phosphate [Ca(H₂PO₄)₂·H₂O] as the only product in the form of single crystals. Solution thermolysis of 2 in protic solvents such as water and methanol can be biased to produce other calcium phosphate biomaterials such as hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂]and calcium monohydrogen phosphate [Ca(HPO₄)] in the presence of additional calcium precursors such as CaO and Ca(OMe)₂, respectively.

Green synthesis of silver nanoparticles using bovine skin gelatin and its antibacterial effect on clinical bacterial isolates

Nanoparticles are being increasingly used in day-to-day life. Therefore, concerns have been raised regarding their interactions with the surrounding environment. This study focused on a simple green method for synthesizing silver nanoparticles (Ag-NPs) in an autoclave at 15 psi (103 kPa) and 121°C. An aqueous solution of AgNO₃ as a precursor of Ag-NPs and gelatin (type B) reducing and/or stabilizing (capping) agent were used. The effect of various AgNO₃ concentrations of certain gelatin concentration and various gelatin concentrations at constant AgNO₃ concentration, and autoclaving time, was studied. UV-Vis spectra ascribed that the presence of localized surface plasmon resonance (SPR) of the synthesized Ag-NPs. TEM images and the selected area of electron diffraction confirmed, the formation of Ag-NPs with a diameter of approximately 5 ±0.35 nm. Furthermore, FT-IR revealed that a gelatin polymer matrix stabilized the synthesized Ag-NPs. The Well diffusion assay was used to test the effect of Ag-NPs on six clinical bacterial isolates, where Gram positive bacteria were more susceptible to Ag-NPs than Gram negative bacteria. Therefore, Ag-NPs capped by gelatin have remarkable potential effect as an antibacterial agent, and they not only have various medical applications but can also be used in biological, pharmaceutical and industrial fields.