The Uniform Distribution of Hydroxyapatite in a Polyurethane Foam-Based Scaffold (PU/HAp) to Enhance Bone Repair in a Calvarial Defect Model.

Polyurethane (PU) is a promising material for addressing challenges in bone grafting. This study was designed to enhance the bone grafting capabilities of PU by integrating hydroxyapatite (HAp), which is known for its osteoconductive and osteoinductive potential. Moreover, a uniform distribution of HAp in the porous structure of PU increased the effectiveness of bone grafts. PEG/APTES-modified scaffolds were prepared through self-foaming reactions. A uniform pore structure was generated during the spontaneous foaming reaction, and HAp was uniformly distributed in the PU structure (PU15HAp and PU30HAp) during foaming. Compared with the PU scaffolds, the HAp-modified PU scaffolds exhibited significantly greater protein absorption. Importantly, the effect of the HAp-modified PU scaffold on bone repair was tested in a rat calvarial defect model. The microstructure of the newly formed bone was analyzed with microcomputed tomography (µ-CT). Bone regeneration at the defect site was significantly greater in the HAp-modified PU scaffold group than in the PU group. This innovative HAp-modified PU scaffold improves current bone graft materials, providing a promising avenue for improved bone regeneration.

Researching the Effectiveness of an Online COVID-19 Educational Module among Community Health Nursing Students.

PURPOSE: The purpose of this research study was to determine the effectiveness of an innovative online COVID-19 educational module among community health nursing students. DESIGN: Mixed-methods study. METHODS: The sample (N = 86) consisted of prelicensure and postlicensure community health nursing students, who completed a pretest, COVID-19 educational intervention, and posttest. FINDINGS: The majority of participants' scores increased from pretest to posttest, and most participants strongly agreed that the COVID-19 educational module was effective. Strategies to address vaccine hesitancy, information learned and found most helpful, and plans for application and utilization of this knowledge were revealed. CONCLUSIONS: An online COVID-19 community health nursing educational intervention was effective at improving participants' knowledge, confidence, and attitudes regarding COVID-19. CLINICAL EVIDENCE: Online COVID-19 community health nursing education was an effective strategy for increasing preparation for this pandemic and the format can be useful to utilize for future public health emergencies.

A Multifunctional Polyethylene Glycol/Triethoxysilane-Modified Polyurethane Foam Dressing with High Absorbency and Antiadhesion Properties Promotes Diabetic Wound Healing.

The delayed healing of chronic wounds, such as diabetic foot ulcers (DFUs), is a clinical problem. Few dressings can promote wound healing by satisfying the demands of chronic wound exudate management and tissue granulation. Therefore, the aim of this study was to prepare a high-absorption polyurethane (PU) foam dressing modified by polyethylene glycol (PEG) and triethoxysilane (APTES) to promote wound healing. PEG-modified (PUE) and PEG/APTES-modified (PUESi) dressings were prepared by self-foaming reactions. Gauze and PolyMem were used as controls. Next, Fourier transform-infrared spectroscopy, thermomechanical analyses, scanning electron microscopy and tensile strength, water absorption, anti-protein absorption, surface dryness and biocompatibility tests were performed for in vitro characterization. Wound healing effects were further investigated in nondiabetic (non-DM) and diabetes mellitus (DM) rat models. The PUE and PUESi groups exhibited better physicochemical properties than the gauze and PolyMem groups. Moreover, PUESi dressing showed better anti-adhesion properties and absorption capacity with deformation. Furthermore, the PUESi dressing shortened the inflammatory phase and enhanced collagen deposition in both the non-DM and DM animal models. To conclude, the PUESi dressing not only was fabricated with a simple and effective strategy but also enhanced wound healing via micronegative-pressure generation by its high absorption compacity with deformation.

Assessment of reinforced poly(ethylene glycol) chitosan hydrogels as dressings in a mouse skin wound defect model.

Wound dressings of chitosan are biocompatible, biodegradable, antibacterial and hemostatic biomaterials. However, applications for chitosan are limited due to its poor mechanical properties. Here, we conducted an in vivo mouse angiogenesis study on reinforced poly(ethylene glycol) (PEG)-chitosan (RPC) hydrogels. RPC hydrogels were formed by cross-linking chitosan with PEGs of different molecular weights at various PEG to chitosan ratios in our previous paper. These dressings can keep the wound moist, had good gas exchange capacity, and was capable of absorbing or removing the wound exudate. We examined the ability of these RPC hydrogels and neat chitosan to heal small cuts and full-thickness skin defects on the backs of male Balb/c mice. Histological examination revealed that chitosan suppressed the infiltration of inflammatory cells and accelerated fibroblast proliferation, while PEG enhanced epithelial migration. The RPC hydrogels promoted wound healing in the small cuts and full layer wounds. The optimal RPC hydrogel had a swelling ratio of 100% and a water vapor transmission rate (WVTR) of about 2000 g/m(2)/day. In addition, they possess good mechanical property and appropriate degradation rates. Thus, the optimal RPC hydrogel formulation functioned effectively as a wound dressing and promoted wound healing.

Effects of types and length of soft-segments on the physical properties and blood compatibility of polyurethanes.

Segmented polyurethane (SPU) materials based on different soft-segment component (PPG, PTMO and PBA) and various length of soft-segment (molecular weight of PBA: 500, 700 and 1000) were synthesized in this research. The soft-segment components were synthesized from polyether-polyols (PPG and PTMO) or from polyester-polyol (PBA). The physical properties and structure characterization of the synthesized SPUs were fully investigated using differential scanning calorimetry (DSC) analysis, and stress-strain measurements. Blood compatibility was evaluated with the platelet adhesion ratio (PAR) and the morphological observation for adhering platelets. Our results showed that the physical properties and blood compatibility of SPUs were closely related to its composition, which was controlled by (1) the types of the soft-segment component employed and (2) the length of soft segments. Polyether-polyol-based SPUs exhibited greater phase separations, poorer tensile strengths, and better blood compatibility, compared with polyester-polyol-based SPUs. SPUs with shorter soft-segment component exhibited greater phase mixing, higher tensile strength, but lower blood compatibility of SPUs, as compared with its counterparts with longer soft-segment component.