Enhanced water absorption of tissue paper by cross-linking cellulose with poly(vinyl alcohol)

Sustainable Synthesis of Multifunctionalized Amoxicillin-Loaded Biopolymer Foams

The development of biocompatible biopolymer foams loaded with antibiotics is crucial to advancing drug delivery systems in biomedical engineering. These materials offer controlled drug release and specialized functionalities for improved therapeutic outcomes. This study presents the development and characterization of antimicrobial polymeric biofoam materials loaded with the drug amoxicillin (AMX). The sustainable synthesis of these biopolymer foams involves a cost-effective, eco-friendly method that incorporates natural starch within poly(vinyl alcohol) (PVA) through an aldehyde cross-linking/stabilizing process. The highly porous structure of the biofoams enabled effective impregnation of the AMX drug using an innovative process involving ultrasonication and vacuum pressure to maximize efficiency and minimize biomaterial loss. The findings demonstrate the potential of these PVA/starch-based biofoams as versatile drug delivery systems with desirable physicochemical and biological characteristics. Detailed investigations were conducted to evaluate morphological features, chemical properties, swelling behavior, in vitro biodegradability, drug release profiles, cell culture, and antimicrobial activity tests of the prepared biofoam samples. Investigating the effect of controlled loading of AMX under laboratory conditions on its release profile and studying its biodegradation in various environments over time represent a critical aspect of this research. The optimal release profile under physiological conditions and the potent inhibition of bacterial growth against Escherichia coli and Staphylococcus aureus microorganisms by AMX-loaded biofoam materials highlight their potential for biomedical applications. These materials show promise for the in vivo administration and local treatment of bacterial infections.

Investigation of Calcium Phosphate-Based Biopolymer Composite Scaffolds for Bone Tissue Engineering

We present a novel method for preparing bioactive and biomineralized calcium phosphate (mCP)-loaded biopolymer composite scaffolds with a porous structure. Two types of polymers were investigated as matrices: one natural, cellulose acetate (CA), and one synthetic, polycaprolactone (PCL). Biomineralized calcium phosphate particles were synthesized via wet chemical precipitation, followed by the addition of organic biominerals, such as magnesium gluconate and zinc gluconate, to enhance the bioactivity of the pure CP phase. We compared the morphological and chemical characteristics of the two types of composites and assessed the effect of biomineralization on the particle structure of pure CP. The precipitated CP primarily consisted of nanocrystalline apatite, and the addition of organic trace elements significantly influenced the morphology by reducing particle size. FE-SEM elemental mapping confirmed the successful incorporation of mCP particles into both CA and PCL polymer matrices. Short-term immersion tests revealed that the decomposition rate of both composites is slow, with moderate and gradual ionic dissolution observed via ICP-OES measurements. The weight loss of the PCL-based composite during immersion was minimal, decreasing by only 0.5%, while the CA-based composite initially exhibited a slight weight increase before gradually decreasing over time.

Development of a Method for Peeling Off Paper from Celluloid Pictures for Animation Films

During the storage of celluloid pictures for animation films over half a century, an interleave paper adhered to acrylic paint. The purpose of this study is to establish a methodology to cleanly remove the paper from the paint. A layered film, a replica of the celluloid pictures, adhered with paper was prepared and immersed in water or ethanol. The effect of these solvents on the peeling behavior was investigated using a peel test. The maximum peel force for the dry layered film in was distributed at ~0.5 N, independently of the peel speed. The peel force was significantly reduced after the layered film was immersed in pure water or ethanol. A morphological observation revealed that the dry paper was peeled off via the cohesive failure of the paper. After the layered film was immersed in pure water, the paper was also peeled off via cohesive failure. The layered film immersed in ethanol was peeled off at the paper/paint interface. To clear the effect of the volume change in the paint on peel behavior, the relative volume was determined via image analysis. The relative volume of paint was 1.56 in pure water and 1.37 in ethanol. It can be considered that the large difference in the volume of paint induces a large shear stress at the paint/paper interface.

Influence of Functional Bio-Based Coatings including Chitin Nanofibrils or Polyphenols on Mechanical Properties of Paper Tissues

The paper tissue industry is a constantly evolving sector that supplies markets that require products with different specific properties. In order to meet the demand of functional properties, ensuring a green approach at the same time, research on bio-coatings has been very active in recent decades. The attention dedicated to research on functional properties has not been given to the study of the morphological and mechanical properties of the final products. This paper studied the effect of two representative bio-based coatings on paper tissue. Coatings based on chitin nanofibrils or polyphenols were sprayed on paper tissues to provide them, respectively, with antibacterial and antioxidant activity. The chemical structure of the obtained samples was preliminarily compared by ATR-FTIR before and after their application. Coatings were applied on paper tissues and, after drying, their homogeneity was investigated by ATR-FTIR on different surface areas. Antimicrobial and antioxidant properties were found for chitin nanofibrils- and polyphenols-treated paper tissues, respectively. The mechanical properties of treated and untreated paper tissues were studied, considering as a reference the same tissue paper sample treated only with water. Different mechanical tests were performed on tissues, including penetration, tensile, and tearing tests in two perpendicular directions, to consider the anisotropy of the produced tissues for industrial applications. The morphology of uncoated and coated paper tissues was analysed by field emission scanning electron microscopy. Results from mechanical properties evidenced a correlation between morphological and mechanical changes. The addition of polyphenols resulted in a reduction in mechanical resistance, while the addition of chitin enhanced this property. This study evidenced the different effects produced by two novel coatings on paper tissues for personal care in terms of properties and structure.