Polymers and polymeric composites have steadily reflected their importance in our daily life. Blending poly(vinyl alcohol) (PVA) with a potentially useful natural biopolymers such as hydroxypropyl cellulose (HPC) seems to be an interesting way of preparing a polymeric blends. In the present work, blends of PVA/HPC of compositions (100/0, 90/10, 75/25, 50/50, 25/75, and 0/100 wt/wt%) were prepared to be used as bioequivalent materials. Thermal analyses [differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)], and X-ray diffraction (XRD) were employed to characterize and reveal the miscibility map and the structural properties of such blend system. The obtained results of the thermal analyses showed variations in the glass transition temperature (T_g) indicating the miscibility of the blend systems. Moreover, the changes in the melting temperature (Tm), shape and area were attributed to the different degrees of crystallinity and the existence of polymer-polymer interactions between PVA and HPC molecules. The X-ray diffraction (XRD) analysis showed broadening and sharpening of peaks at different HPC concentrations with PVA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo-polymers PVA and HPC is possible. The results showed that HPC doped in PVA film can improve the thermal stability of the film under investigation, leading to interesting technological applications

The authors describe a case of a 29-year-old man with clinical and radiological features of ileocaecal Crohn's disease. He had previously been investigated for painless macroscopic haematuria and a renal biopsy had revealed IgA nephropathy. Despite medical treatment, regular exacerbations of Crohn's disease were associated with deterioration in renal function and the development of haematuria. The patient eventually underwent surgical resection of the terminal ileum and caecum. His renal disease has remained quiescent for the last 5 years following resection.

No abstract

The aim of the present study was to prepare and characterize nanocomposite films to improve the treatment of skin wounds by applying the film as a bandage. To modify chitosan (Cs) and to prepare nanocomposites, a mixture between titanium dioxide nanoparticles (TiO 2 NPs) was performed at different concentrations (2, 5, 10 and 15 wt%) and oleic acid (OA). The thin nanocomposite films were prepared by using casting method. The prepared films (Cs, Cs/TiO 2 NPs, Cs/OA and Cs/OA/TiO 2 NPs) were described by water absorption (swelling study) and biological degradation. Physico-chemical characterizations of Cs, Cs/OA, Cs/TiO 2 NPs and Cs/OA/TiO 2 NPs (with only 15 wt% TiO 2 NPs) films were determined by X-ray diffraction, transmission high-resolution electron microscopy, field emission scanning electron microscopy, thermal analysis and Fourier transform infrared spectroscopy as well as their mechanical properties. Antimicrobial activity against microorganisms has been studied to assess activity against bacteria. The prepared nanocomposite films showed good antimicrobial activity for both Gram-positive and Gram-negative bacteria. The therapeutic effects of Cs-TiO 2 NPs-oleic acid nanocomposites on healing excision wounds were studied in rat animal model. The data obtained revealed that groups treated with nanocomposites showed enhancement wound closure and speed up wound healing time. K E Y W O R D S antimicrobial activity, chitosan and oleic acid, chitosan and titanium dioxide nanoparticles, nanocomposites films, wound healing 1 | INTRODUCTION Bionanocomposites are beneficial and have been used in a wide range of applications in many fields such as physical, biological, biomedical and pharmaceutical applications (Díez-Pascual, 2019; Loureiro, Azoia, Gomes, & Cavaco-Paulo, 2016; Nikalje, 2015). Nanoparticles are an important component of many classes of biopolymers and bionanocomposites (Lenart & Hore, 2018). Numerous research has stated that TiO 2 nanoparticles at a low content (1-5%) may improve the physical-thermal properties of biocomposite films (Oleyaei, Almasi, Ghanbarzadeh, & Moayedi, 2016; Zhang et al., 2017). Khan and his colleagues reviewed a detailed overview of the properties, and applications of nanoparticles (NPs) present in various forms (Khan, Saeed, & Khan, 2019). Wound dressings develop according to the cause of different wounds. Various types of wound dressings, for example, xerogels, charcoal, alginate, chitosan, and hydrogel, have been introduced for this purpose (Abbasalipour, Mirjalili, Khajavi, & Majidi, 2014).

In the present work, composites of poly(methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%) were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (T g), the melting temperature (T m), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO 2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO 2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homopolymers PMMA and nano-TiO 2 powder is possible. The results showed that nano-TiO 2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, leading to interesting technological applications.

No abstract

Electrospun nano-polycaprolactone (PCL) is an ideal candidate for biomedical applications, as it mimics the extracellular matrix and possesses good biocompatibility, biodegradability and mechanical properties. Formic acid/acetic acid (FA/AA) and formic acid/acetone (FA/A) solvent systems were reported to be the safest solvents for the preparation of nanoscale electrospun polycaprolactone and they are also a common solvent with many natural polymers. In the present study a comparison between the electrospun fibers produced by the two systems was done. The optimum conditions for preparing PCL nanofibers were studied. The results indicated that finer fibers were found for formic acid/acetic acid in comparison with those produced by formic acid/acetone solvent system. In addition, it was found that optimum conditions for PCL nanofibers electrospinning were detected for 70:30 FA/AA solvent ratio with 15% PCL concentration and a tip to collector distance of 12.5 cm at 20 kV.

No abstract