Search Results (2,777)

The development of active food packaging has evolved rapidly in recent years, offering innovative solutions to enhance food preservation and safety while addressing sustainability challenges. This review compiles and analyzes recent advancements (2019–2024) in release-type active packaging, focusing on essential oils, natural extracts, and phenolic compounds as active agents. Primarily plant-derived, these compounds exhibit significant antioxidant and antimicrobial activities, extending shelf life and enhancing food quality. Technological strategies such as encapsulation and polymer blending have been increasingly adopted to overcome challenges related to volatility, solubility, and sensory impact. Integrating bio-based polymers, including chitosan, starch, and polylactic acid, further supports the development of environmentally friendly packaging systems. This review also highlights trends in compound-specific research, release mechanisms, and commercial applications, including a detailed analysis of patents and case studies across various food matrices. These developments have already been translated into practical applications, such as antimicrobial sachets for meat and essential oil-based pads for fresh produce. Moreover, by promoting the valorization of agro-industrial by-products and the use of biodegradable materials, emission-type active packaging contributes to the principles of the circular economy. This comprehensive overview underscores the potential of natural bioactive compounds in advancing sustainable and functional food packaging technologies. Full article

In this study, multicomponent PLA-based biocomposites were developed. In particular, both native fibrous cellulose and cellulose with modified morphology obtained through ball milling treatments were incorporated into the polyester matrix in combination with an oligomeric plasticizer, specifically a lactic acid oligomer (OLA). The resulting materials were analyzed in terms of their morphology, thermal and mechanical properties over time, water vapor permeability, and degradation under soil burial conditions in comparison to neat PLA and unplasticized PLA/cellulose composites. The cellulose phase significantly affected the mechanical properties and enhanced their long-term stability, addressing a common limitation of PLA/plasticizer blends. Additionally, water vapor permeability increased in all composites. Finally, the ternary systems exhibited a significantly higher degradation rate in soil burial conditions compared to PLA, evidenced by larger weight loss and reduction in the molecular weight of the PLA phase. The degradation rate was notably influenced by the morphology of the cellulose phase. Full article

This study aims to analyze the bending behavior of polylactic acid (PLA) structures made by fusion deposition modeling (FDM) technology. The investigation analyzed chiral structures such as lozenge and clepsydra, as well as geometries with wavy patterns such as roller and Es, in addition to a honeycomb structure. All geometries have a relative density of 50%. After being subjected to three-point bending tests, the capacity to spring back with respect to the bending angle and the shape recovery of the structures were measured. The roller and lozenge structures demonstrated the best performance, with shape recovery assessed through three consecutive hot water immersion cycles. The lozenge structure exhibits 25% higher energy absorption than the roller, but the latter ensures better replicability and shape stability. Additionally, the roller absorbs 15% less energy than the lozenge, which experiences a 27% decrease in absorption between the first and second cycle. This work provides new insights into the bending-based energy absorption and recovery behavior of PLA metamaterials, relevant for applications in adaptive and energy-dissipating systems. Full article

This study presents the fabrication and characterization of sustainable polylactic acid (PLA)-based biocomposites reinforced with bio-origin fillers derived from food waste: seashells, eggshells, walnut shells, and spent coffee grounds. All fillers were introduced at 15 wt% into a commercial PLA matrix modified with a compatibilizer to improve interfacial adhesion. Mechanical properties (tensile, flexural, and impact strength), morphological characteristics (via SEM), and hydrolytic aging behavior were evaluated. Among the tested systems, PLA reinforced with seashells (PLA15S) and coffee grounds (PLA15C) demonstrated the most balanced mechanical performance, with PLA15S achieving a tensile strength increase of 72% compared to neat PLA. Notably, PLA15C exhibited the highest stability after 28 days of hydrothermal aging, retaining ~36% of its initial tensile strength, outperforming other systems. In contrast, walnut-shell-filled composites showed the most severe degradation, losing over 98% of their mechanical strength after aging. The results indicate that both the physicochemical nature and morphology of the biofiller play critical roles in determining mechanical reinforcement and degradation resistance. This research underlines the feasibility of valorizing agri-food residues into biodegradable, semi-structural PLA composites for potential use in sustainable packaging or non-load-bearing structural applications. Full article

Biodegradable polymers offer environmental advantages compared to fossil-based alternatives, but they currently lack the stretchability required for demanding applications such as mesh fabrics for woven flexible intermediate bulk container (FIBC) bags and stretch, shrink, and cling films. The goal of this research is to enhance the stretchability of biodegradable blends based on 80% poly(butylene adipate-co-terephthalate) (PBAT) and 20% poly(lactic acid) (PLA) through reactive extrusion. Radical initiator (dicumyl peroxide (DCP)) and chain extenders (maleic anhydride (MA), glycidyl methacrylate (GMA)) were employed to improve the melt strength and elasticity of the extruded films. The reactive blends were initially prepared using a batch mixer and subsequently compounded in a twin-screw extruder. Films were produced via cast extrusion. 0.1% wt. DCP led to a 200% increase in elongation at break and a 44% improvement in tensile strength. Differential scanning calorimetry and scanning electron microscopy revealed enhanced miscibility between components. Shear and complex viscosity increased by 38% and 85%, compared to the neat blend, respectively. Reactive extrusion led to a better dispersion and distribution of the phases. An improved interfacial adhesion between the phases, in addition to higher molecular weight, led to enhanced melt strength and improved stretchability. Full article

Background and Objectives: Although cyanoacrylate–polylactic acid (CA + PLA) patches shorten the time to hemostasis after partial hepatectomy, their long-term biocompatibility remains uncertain. We compared the 5-month histopathological footprint of a novel CA + PLA patch (Study group) with a licensed fibrinogen/thrombin matrix (TachoSil^® group) and electrocautery (Control group). Methods: Thirty-three male Wistar rats underwent a 3 × 1.5 cm hepatic segment resection and were randomized to the Control (n = 5), Study (n = 14), or TachoSil^® (n = 14) group. The animals were sacrificed on postoperative day (POD) 50, 100, or 150. Blinded semiquantitative scoring (0–3) was used to capture inflammation intensity, and the number of neutrophils (PMNs), lymphocytes (Ly’s), isolated histiocytes, and foreign-body giant cells (FBGCs). Results: The proportions of animals in each group across the different sacrifice time points were homogeneous (χ² = 4.34, p = 0.36). The median inflammation remained mild (2 [IQR 1–2]) in the Control and Study groups but lower in the TachoSil^® group (1 [1–2], p = 0.47). The FBGC scores differed markedly (score ≥ 2: 64% in Study, 0% in Control, 14% in TachoSil^®; p < 0.001). Fibrosis occurred almost exclusively in the Study group (79% vs. 0%; χ² = 22.4, p < 0.001). Mature vessels were most frequently observed in the TachoSil^® group (50%, aOR = 5.1 vs. Study, p = 0.04). Abscesses only developed in the Study group (29%, p = 0.046). Within the TachoSil^® group, inflammation (ρ = −0.62, p = 0.019) and Ly infiltration (ρ = −0.76, p = 0.002) declined with time; no significant temporal trends emerged in the Study group. Conclusions: At the five-month follow-up, there was an exuberant foreign-body reaction, dense collagen deposition, and a higher abscess rate around the CA + PLA patch compared with both TachoSil^® and cautery. Conversely, TachoSil^® evolved toward a mature, well-vascularized scar with waning inflammation. These findings underscore the importance of chronic-phase evaluation before clinical adoption of new hemostatic biomaterials. Full article

This study examines the effect of elevated printing speeds (100–600 mm/s) on the dimensional accuracy and tensile strength of PLA components fabricated via fused deposition modeling (FDM). To isolate the influence of printing speed, all other parameters were kept constant, and two filament variants—natural (unpigmented) and black PLA—were analyzed. ISO 527-2 type 1A specimens were produced and tested for dimensional deviations and ultimate tensile strength (UTS). The results indicate that printing speed has a marked impact on both geometric precision and mechanical performance. The optimal speed of 300 mm/s provided the best compromise between dimensional accuracy and tensile strength for both filaments. At speeds below 300 mm/s, under-extrusion caused weak layer bonding and air gaps, while speeds above 300 mm/s led to over-extrusion and structural defects due to thermal stress and rapid cooling. Black PLA yielded better dimensional accuracy at higher speeds, with cross-sectional deviations between 2.76% and 5.33%, while natural PLA showed larger deviations of up to 8.63%. However, natural PLA exhibited superior tensile strength, reaching up to 46.59 MPa, with black PLA showing up to 13.16% lower UTS values. The findings emphasize the importance of speed tuning and material selection for achieving high-quality, reliable, and efficient FDM prints. Full article

To address the growing demand for sustainable materials in advanced manufacturing, the objective of this study was to develop and characterize a novel 3D-printable biocomposite using ruminant-digested corn stover (DCS) as a reinforcement for polylactic acid (PLA). The methodology involved systematically optimizing DCS particle size (80–140 mesh) and loading concentration (5–20 wt.%), followed by fabricating composite filaments via melt extrusion and 3D printing test specimens. The resulting materials were comprehensively characterized for their morphological, physical, and mechanical properties. The optimal formulation, achieved with 120-mesh particles at 15 wt.% loading, exhibited a 15.6% increase in tensile strength to 64.17 MPa and a 21.1% enhancement in flexural modulus to 4.19 GPa compared to neat PLA. In addition to the mechanical improvements, the biocomposite offers an advantageous density reduction, enabling the fabrication of lightweight structures for resource-efficient applications. Comprehensive characterization revealed effective interfacial integration and uniform fiber dispersion, validating biological preprocessing as a viable method for unlocking the reinforcement potential of this abundant biomass. While the composite exhibits characteristic trade-offs, such as reduced impact strength, the overall performance profile makes it a promising candidate for structural applications in sustainable manufacturing. This research establishes a viable pathway for agricultural waste valorization, demonstrating that biological preprocessing can convert agricultural residues into value-added engineering materials for the circular bioeconomy. Full article

Although PLA is an attractive biodegradable polymer, its degradation under natural conditions is often slow. This study investigates whether incorporating pounamu (New Zealand jade) particles into PLA can enhance its biodegradation rate under composting conditions at room temperature. PLA composites containing 0 to 15 wt% pounamu were fabricated using both compression molding and 3D printing. A simple, reproducible protocol based on residual mass measurement was developed to monitor the biodegradation process over a 12-month period. The results showed that increasing pounamu content consistently accelerated mass loss of the composite in the compost, indicating enhanced biodegradation. The 3D-printed samples degraded more rapidly than compression-molded ones. This was attributed to the layered structure, internal microcavities, and lower crystallinity of the 3D-printed samples, which provided greater surface area and accessibility for microbial activity. These findings highlight the dual role of pounamu as both a crystallization promoter and a facilitator of biodegradation and underscore the importance of the processing method when designing biodegradable polymer composites for real-world applications. Full article

In recent years, significant progress has been made in breast reconstructive surgery, particularly with the use of three-dimensional (3D) disassemblable scaffolds. Reconstructive plastic surgery aimed at restoring the shape and size of the mammary gland offers medical, psychological, and social benefits. Using autologous tissues allows surgeons to recreate the appearance of the mammary gland and achieve tactile sensations similar to those of a healthy organ while minimizing the risks associated with implants; 3D disassemblable scaffolds are a promising solution that overcomes the limitations of traditional methods. These constructs offer the potential for patient-specific anatomical adaptation and can provide both temporary and long-term structural support for regenerating tissues. One of the most promising approaches in post-mastectomy breast reconstruction involves the use of autologous cellular and tissue components integrated into either synthetic scaffolds—such as polylactic acid (PLA), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), and polycaprolactone (PCL)—or naturally derived biopolymer-based matrices, including alginate, chitosan, hyaluronic acid derivatives, collagen, fibrin, gelatin, and silk fibroin. In this context, two complementary research directions are gaining increasing significance: (1) the development of novel hybrid biomaterials that combine the favorable characteristics of both synthetic and natural polymers while maintaining biocompatibility and biodegradability; and (2) the advancement of three-dimensional bioprinting technologies for the fabrication of patient-specific scaffolds capable of incorporating cellular therapies. Such therapies typically involve mesenchymal stromal cells (MSCs) and bioactive signaling molecules, such as growth factors, aimed at promoting angiogenesis, cellular proliferation, and lineage-specific differentiation. In our review, we analyze existing developments in this area and discuss the advantages and disadvantages of 3D disassemblable scaffolds for mammary gland reconstruction, as well as prospects for their further research and clinical use. Full article

Three-dimensional cell culture systems are relevant in vitro models for studying cellular behavior. In this regard, this present study investigates the interaction between human osteoblast-like cells and 3D-printed scaffolds mimicking physiological and osteoporotic bone structures under simulated microgravity conditions. The objective is to assess the effects of scaffold architecture and dynamic culture conditions on cell adhesion, proliferation, and metabolic activity, with implications for osteoporosis research. Polylactic acid scaffolds with physiological (P) and osteoporotic-like (O) trabecular architectures were 3D-printed by means of fused deposition modeling technology. Morphometric characterization was performed using micro-computed tomography. Human osteoblast-like SAOS-2 and U2OS cells were cultured on the scaffolds under static and dynamic simulated microgravity conditions using a rotary cell culture system (RCCS). Scaffold biocompatibility, cell viability, adhesion, and metabolic activity were evaluated through Bromodeoxyuridine incorporation assays, a water-soluble tetrazolium salt assay, and an enzyme-linked immunosorbent assay of tumor necrosis factor-α secretion. Both scaffold models supported osteoblast-like cell adhesion and growth, with an approximately threefold increase in colonization observed on the high-porosity O scaffolds under dynamic conditions. The dynamic environment facilitated increased surface interaction, amplifying the effects of scaffold architecture on cell behavior. Overall, sustained cell growth and metabolic activity, together with the absence of detectable inflammatory responses, confirmed the biocompatibility of the system. Scaffold microstructure and dynamic culture conditions significantly influence osteoblast-like cell behavior. The combination of 3D-printed scaffolds and a RCCS bioreactor provides a promising platform for studying bone remodeling in osteoporosis and microgravity-induced bone loss. These findings may contribute to the development of advanced in vitro models for biomedical research and potential countermeasures for bone degeneration. Full article

Polylactic acid (PLA) is a renewable biopolymer that has attracted considerable interest due to its ability to replace petroleum-based synthetic polymers, thereby offering a more sustainable alternative to global environmental concerns. This study focused on evaluating the effect of catalyst concentration and reaction time on the efficiency of PLA synthesis via the Ring-Opening Polymerization (ROP) technique. The process involved a lactic acid esterification stage (using 88% lactic acid) to obtain lactide, employing 40% and 60% (v/v) sulfuric acid concentrations, followed by polymerization at various reaction times (10, 15, 20, and 30 min). Analysis of variance (ANOVA) results revealed that the 40% catalyst concentration had a statistically significant effect on polymer yield (p = 0.032), whereas reaction time showed no statistical significance (p = 0.196), although the highest yields were recorded at 10 and 15 min. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of the characteristic functional groups of PLA, and Differential Scanning Calorimetry (DSC) revealed a semi-crystalline structure with a high melting temperature, indicating good thermal stability. These results validate the viability of PLA as a functional and sustainable biopolymer. Full article

Biodegradable polymer composites offer promising alternatives to petroleum-based plastics, supporting the principles of a zero waste and circular economy. This study investigates the reinforcing potential of alkali-treated wood flour derived from recycled pine (Pinus brutia Ten.) and poplar (Populus alba L.) waste wooden pallets in poly(lactic acid) (PLA) biocomposites. Wood flour was initially recovered through grinding and screening during recycling, followed by alkali treatment via a green chemistry approach to enhance interfacial bonding with the PLA matrix. The impact of alkali concentration and two fabrication methods—additive manufacturing (AM) and injection molding (IM)—on the properties of developed biocomposite materials was assessed through mechanical, physical, morphological, and thermal analyses. IM samples outperformed AM counterparts, with the IM PLA containing 30 wt% wood flour (alkali-treated with 10% solution) showing the highest mechanical gains: tensile (+71.35%), flexural (+64.74%), and hardness (+2.62%) compared to untreated samples. Moreover, the AM sample with 10 wt% wood flour and 10% alkali treatment showed a 49.37% decrease in water absorption compared to the untreated sample, indicating improved hydrophobicity. Scanning electron microscopy confirmed that alkali treatment reduced void content and enhanced morphological uniformity, while thermal properties remained consistent across fabrication methods. This work introduces a green composite using non-toxic materials and treatments, facilitating eco-friendly production aligned with zero waste and circular economy principles throughout the manufacturing lifecycle. Full article

This study analyses the application of the Friction Stir Welding (FSW) process on polymeric materials manufactured by additive manufacturing (AM), specifically with polylactic acid (PLA). FSW is a solid-state welding process characterized by its low heat input and minimal distortion, which makes it ideal for the assembly of complex or large components made by additive manufacturing. To evaluate its effectiveness, a portable FSW device was developed for the purpose of joining PLA specimens made by AM using different filler densities (15% and 100%). Two tool geometries (a cylindrical and truncated cone) were utilized by varying the parameters of rotational speed, tilt angle, and feed rate. The results revealed two different process stages, transient and steady-state, and showed differences in weld quality depending on the material density, tool type, and material addition. The study confirms the viability of FSW for joining PLA parts made by AM and suggests potential applications in industries that require robust and precise joints in plastic parts, thereby helping hybrid manufacturing to progress. Full article

Since the mid-19th century, researchers have explored the potential of bio-based polymeric materials for diverse applications, with particular promise in medicine. This review provides a focused and detailed examination of natural and synthetic biopolymers relevant to tissue engineering and biomedical applications. It emphasizes the structural diversity, functional characteristics, and processing strategies of major classes of biopolymers, including polysaccharides (e.g., hyaluronic acid, alginate, chitosan, bacterial cellulose) and proteins (e.g., collagen, silk fibroin, albumin), as well as synthetic biodegradable polymers such as polycaprolactone, polylactic acid, and polyhydroxybutyrate. The central aim of this manuscript is to elucidate how intrinsic properties—such as molecular weight, crystallinity, water retention, and bioactivity—affect the performance of biopolymers in biomedical contexts, particularly in drug delivery, wound healing, and scaffold-based tissue regeneration. This review also highlights recent advancements in polymer functionalization, composite formation, and fabrication techniques (e.g., electrospinning, bioprinting), which have expanded the application potential of these materials. By offering a comparative analysis of structure–property–function relationships across a diverse range of biopolymers, this review provides a comprehensive reference for selecting and engineering materials tailored to specific biomedical challenges. It also identifies key limitations, such as production scalability and mechanical performance, and suggests future directions for developing clinically viable and environmentally sustainable biomaterial platforms. Full article