Advanced Industrial and Engineering Polymer Research最新文献

Poly (lactic acid) (PLA) foams have demonstrated a high variety of functional characteristics, still, the rigidity of this cellular material remains a major limiting factor when it comes to implementation options. In this contribution, PLA foams with outstanding flexibility were created for the first time by a new approach of uniaxial stretching and immediate relaxation following supercritical CO₂-assisted extrusion foaming. Instead of improving the resilience of the PLA raw material, structural elasticity of the foam was achieved via altering the deformation mechanism from cell wall collapse or rupture towards reversible and extensive flexural strain. In addition, PLA foams with excellent piezoelectric properties were also achieved via high-voltage corona poling, giving additional function to the lens-like anisotropic foam cells. This foaming technology creates the opportunity to produce PLA piezoelectrets in a way entirely different from the state-of-the-art methods. Correlation between the tensile as well as compression elongations and moduli, cell morphology and longitudinal piezoelectric coefficients (d₃₃) of electretized foam samples were studied. Unprecedented reversible tensile elongations of up to 16% and total elongations of up to 35% were reached, as well as considerable d₃₃ values in the range of 50–320 pC/N were obtained for PLA ferroelectrets.

Polymer blends are mixtures of two or more macromolecular species – polymers and/or copolymers. They are used to increase the range of properties available from existing polymers without synthesizing new ones, which is time consuming and expensive. But most blends are immiscible, and need to be compatibilized. The compatibilization must not only insure improvement in performance, it must be clearly defined with regard to the method and objective. Keeping this view in focus, the present review classifies the main approaches that are available into four well-defined “routes” to compatibilization for various types of polymers and copolymers. Further, the possibility of using an innovative combination of in-situ polymerization and in-situ compatibilization as a new route to polymeric nano-blends is explained. While most of the present narrative deals with different types of binary polymer/copolymer blends, pathways for extension of some of the methods to ternary or multicomponent blending and the significance of the novel composite compatibilizers in this context are also highlighted.

Aim

To evaluate the in vivo toxicity of the anionic nanoliposome formulation containing [hydrogenated soy phosphatidylcholine (HSPC)] and [1,2-distearoyl-sn-glycero-3- phosphoglycerol (DSPG)].

Methods

The anionic nanoliposome formulation was prepared by the lipid film hydration method. To assess the toxicity of anionic nanoliposomes, male and female albino mice were weakly treated with intravenous injection of the formulation (100 μmol/kg) for four weeks. The toxicity study was performed by the subacute protocol, four weeks after the last injection. To this end, the plasma levels of lipid indexes, urea, creatinine, AST, ALT, ALP, and fasting blood glucose (FBG) were measured. To evaluate histopathological alterations, the tissues of the vital organs including the heart, liver, kidneys, spleen, and brain were studied using hematoxylin & eosin (H&E) staining.

Results

The results showed nonsignificant changes in total cholesterol, LDL-C, HDL-C, creatinine, urea, AST, ALP, and ALT in the liposome-treated mice when compared with control mice. However, plasma levels of triglycerides were significantly decreased (by 64.5 ± 15.3 mg/dL, p = 0.001) and (by 58.75 ± 15.3 mg/dL, p = 0.002) in the liposome-treated male and female mice, respectively, when compared with corresponding control mice. The FBG level was significantly increased by154 ± 20 mg/dL, p = 0.001 in the liposome-treated male mice when compared with the control male mice. The PAB level was significantly decreased by 12 ± 4.2 HK, p = 0.03 in the liposome-treated male mice when compared with the control male mice. Histological examination of vital organs indicated no significant differences in tissue damage between the liposome-treated and control mice.

Conclusion

The findings of the present study indicated that DSPG-containing nanoliposome formulation exerted no significant adverse effects on the function of vital organs and blood levels of biochemical biomarkers in healthy mice. However, further investigations are needed to find a safe dose of DSPG liposomes concerning the risk of diabetes.

Recent developments in nanomaterials have come to extensive use in various fields, especially in the biomedical industry. Numerous significant obstacles still need to be overcome, particularly those about utilizing nanomaterials in biomedical science, before they can be used for medicinal purposes. Major issues in biomedicine include biological functioning, harmony, toxic effects, and nano-bio surface properties. Thus, researchers may use cutting-edge characterization approaches to study nanomaterials for biomedical applications. Two-dimensional nanomaterials and polymers are crucial components of biological systems. Polymer-based nanomaterials are flexible and more resistant to chemical attack than other NPs. Polymers easily form composite or functionalization with other NPs to improve their performance compared to the traditional NPs. The current review article discussed nanomaterial performance, including carbon nanotubes (CNTs), graphene, MXene and polymers-based biomedical applications. The current state of nanomaterials in the biomedical area is illustrated in this summary article, along with applications and the significance of characterization approaches. The advanced methods for examining the interior geometry, structure, and morphology of nanomaterials are discussed in this piece of writing, including Transmission electron microscopy (TEM), Scanning electronic microscopy (SEM), Atomic Force Microscopy (AFM), Magnetic resonance force microscopy (MRFM) and X-ray diffraction (XRD). Finally, the authors discussed the issues associated with nanomaterials in biomedical applications.

The study of nanocomposite hydrogels in their various scientific areas has grown remarkably along the years with emergence of various theoretical and experimental techniques. Therefore, this review is categorized to provide a comprehensive guide on the fabrication of nanocomposite hydrogels. In this regard, the type and amounts of nanomaterial, and the hydrogel network formation have a significant impact on the improvement of physical, chemical, and biological properties of hydrogels. It has to be noted that these parameters are dependent on the application of nanocomposite hydrogels.

Therefore, the orientation of the range of nanomaterials, product characteristics, along with sufficient information on the application of these materials, need to be considered to obtain a successful material.

In this review article, the scientific advances in the field of nanocomposite hydrogels, focusing on their types based on the nanoparticle types, and their properties with a new perspective on rheology, self-healing behavior, thermal stability, biologic, and morphology are investigated. Eventually, the applicability of these materials is collected in a comprehensive table in various fields such as biomedical, enhanced oil recovery, agriculture, etc. for the first time presents comparisons with more details.

Additive Manufacturing (AM) has been a noticeable technology and made significant progress since the late 1980s. Despite the tremendous growth, this technology is still facing numerous manufacturing challenges. AM of structures and smart materials such as shape memory polymers and alloys is one of the most actively researched areas in which printed objects can alter their properties and shape when exposed to a stimulus e.g., light, temperature, magnetic fields, pH, and humidity. The AM-build parts which can take advantage of these shape-changing features, lead to the growth of 4D printing by introducing time as a fourth dimension in AM processes. This new field originated in 2013, and since then, it has generated great interest due to its potential to build innovative, multi-functional, self-assembling, and self-repairing components with modifiable properties, shapes, and functionalities. This review article intends to examine the major developments of 4D printing in the biomedical field. The study will provide an overview of various 4D printing technologies including vat photo-polymerization, extrusion-based methods, and material jetting and their uses in the biomedical field. It focuses on smart materials like SMPs, LCEs, SMPAs, etc., and their applications in various industries e.g., mechanical, biomedical, aerospace, etc., and explores external stimuli such as moisture, temperature, pH, magnetic fields, and light. The article delves into the promising applications of 4D printing in biomedical fields such as drug delivery, orthopedics, medical devices, tissue engineering, and dentistry and analyzes the challenges associated with 4D printing in the biomedical field, and suggests the future directions including optimization of printing parameters, and exploration of novel materials to broaden its applications.