Bio-Based and Biodegradable Plastics: From Passive Barrier to Active Packaging Behavior

Natural Alternatives to Non-biodegradable Polymers in 3D Printing of Pharmaceuticals

BACKGROUND

Due to potential toxicity, non-biodegradable polymers used in 3D (3-dimensional) printing of drugs could be dangerous for patient safety and the environment.

OBJECTIVE

This review aims to investigate the toxicity of non-biodegradable polymers and investigate the use of natural materials as an alternative in 3D printing medicines. The study evaluates the dangers connected to 3D printing.

METHODS

A review of the literature on various 3D printing processes, such as inkjet printing, fused filament manufacturing, and extrusion-related 3DP systems, was done for this study. Also, the use of cellulose derivatives and natural materials in 3D printing and their potential as active excipients was proposed.

RESULTS

The review identified potential toxicity risks linked to non-biodegradable polymers used in drug 3D printing. As a potential fix for this issue, the use of natural materials with improved mechanical and thermal properties was explored. The use of cellulose derivatives as an alternative to non-biodegradable polymers in 3D printing pharmaceuticals was also investigated in the study.

CONCLUSION

This study emphasises the significance of evaluating the risks connected to drug 3D printing and recommends using natural materials as an alternative to non-biodegradable polymers. More study is required to create secure and reliable 3D printing processes for pharmaceuticals.

Effects of glycerol and sorbitol on a novel biodegradable edible film based on Malva sylvestris flower gum

There has been an increasing interest in the investigation of novel eco-friendly packaging materials. An edible film based on Malva sylvestris flower gum was fabricated with 40%, 50%, and 60% glycerol and sorbitol using casting method. FTIR analysis was applied to identify the functional groups of films with different concentrations of plasticizers. The lightness of the samples did not affect upon increasing the sorbitol and glycerol; nevertheless, the samples tended to be green and yellow. SEM images indicated that glycerol-based films enjoy heterogeneous and porous surfaces compared to the sorbitol-based samples. Although Tensile Strength and Young's Modulus characteristics declined considerably (p < .05) upon plasticizer addition, elongation at break increased by more than 10% in glycerol-based samples. A significant (p < .05) decrement was observed in the density of film strips via the addition of glycerol and sorbitol. Moisture content of films incorporated with both plasticizers saw a considerable improvement (p < .05) upon increasing the plasticizer concentration from 40% to 60% and is ascribed to the water-holding capacity of plasticizers. Water contact angle and water solubility increased via plasticizer supplementation, which is attributed to the hydrophilic characteristic of glycerol and sorbitol, are in line with SEM analysis.

Biodegradability of Polyolefin-Based Compositions: Effect of Natural Rubber

Recently, environmental problems caused by the overproduction and consumption of synthetic polymer materials led to an urgent need to develop efficient methods for processing plastics. The accumulation of polymer waste for their subsequent incineration does not solve the problem due to the limited areas of landfills for waste storage. In addition, the incineration of polymer waste can cause toxic air pollution, which, in turn, does not contribute to an improvement in the environmental situation. Recycling plastics, although a more environmentally friendly waste disposal method, requires significant labor and energy costs and can be performed a limited number of times. Thus, the most promising solution to this problem is the creation of biodegradable polymers capable of degradation with the formation of simpler chemical structures (water, carbon dioxide, biomass, etc.), which are easily included in the metabolic processes of natural biological systems. The article provides an overview of the main trends in the creation of biodegradable composites for the needs of agriculture. Also, the article proposes a new composition based on polyethylene with natural rubber that surpasses existing biodegradable materials in a number of physical and mechanical characteristics and has the ability to complete biodegradation in 60 months. It is shown that the studies carried out to date indicate that these composites are highly promising for the creation of biodegradable packaging materials with good performance characteristics. Thus, it was concluded that further research on composites based on polyethylene and natural rubber is important.

Options to Improve the Mechanical Properties of Protein-Based Materials

While bio-based but chemically synthesized polymers such as polylactic acid require industrial conditions for biodegradation, protein-based materials are home compostable and show high potential for disposable products that are not collected. However, so far, such materials lack in their mechanical properties to reach the requirements for, e.g., packaging applications. Relevant measures for such a modification of protein-based materials are plasticization and cross-linking; the former increasing the elasticity and the latter the tensile strength of the polymer matrix. The assessment shows that compared to other polymers, the major bottleneck of proteins is their complex structure, which can, if developed accordingly, be used to design materials with desired functional properties. Chemicals can act as cross-linkers but require controlled reaction conditions. Physical methods such as heat curing and radiation show higher effectiveness but are not easy to control and can even damage the polymer backbone. Concerning plasticization, effectiveness and compatibility follow opposite trends due to weak interactions between the plasticizer and the protein. Internal plasticization by covalent bonding surpasses these limitations but requires further research specific for each protein. In addition, synergistic approaches, where different plasticization/cross-linking methods are combined, have shown high potential and emphasize the complexity in the design of the polymer matrix.

Recent Advances in the Development of Smart and Active Biodegradable Packaging Materials

Interest in the development of smart and active biodegradable packaging materials is increasing as food manufacturers try to improve the sustainability and environmental impact of their products, while still maintaining their quality and safety. Active packaging materials contain components that enhance their functionality, such as antimicrobials, antioxidants, light blockers, or oxygen barriers. Smart packaging materials contain sensing components that provide an indication of changes in food attributes, such as alterations in their quality, maturity, or safety. For instance, a smart sensor may give a measurable color change in response to a deterioration in food quality. This article reviews recent advances in the development of active and smart biodegradable packaging materials in the food industry. Moreover, studies on the application of these packaging materials to monitor the freshness and safety of food products are reviewed, including dairy, meat, fish, fruit and vegetable products. Finally, the potential challenges associated with the application of these eco-friendly packaging materials in the food industry are discussed, as well as potential future directions.

Bio-Based Packaging Materials Containing Substances Derived from Coffee and Tea Plants

The aim of the research was to obtain intelligent and eco-friendly packaging materials by incorporating innovative additives of plant origin. For this purpose, natural substances, including green tea extract (polyphenon 60) and caffeic acid, were added to two types of biodegradable thermoplastics (Ingeo™ Biopolymer PLA 4043D and Bioplast GS 2189). The main techniques used to assess the impact of phytocompounds on materials’ thermal properties were differential scanning calorimetry (DSC) and thermogravimetry (TGA), which confirmed the improved resistance to thermo-oxidation. Moreover, in order to assess the activity of applied antioxidants, the samples were aged using a UV aging chamber and a weathering device, then retested in terms of dynamic mechanical properties (DMA), colour changing, Vicat softening temperature, and chemical structure, as studied using FT-IR spectra analysis. The results revealed that different types of aging did not cause significant differences in thermo-mechanical properties and chemical structure of the samples with natural antioxidants but induced colour changing. The obtained results indicate that polylactide (PLA) and Bioplast GS 2189, the plasticizer free thermoplastic biomaterial containing polylactide and starch (referred to as sPLA in the present article), both with added caffeic acid and green tea extract, can be applied as smart and eco-friendly packaging materials. The composites reveal better thermo-oxidative stability with reference to pure materials and are able to change colour as a result of the oxidation process, especially after UV exposure, providing information about the degree of material degradation.