Polysaccharide nanomaterial reinforced starch nanocomposites: A review: Polysaccharide nanomaterial reinforced starch nanocomposites

Carboxymethyl Starch Films as Enteric Coatings: Processing and Mechanistic Insights

This study proposes the application of carboxymethyl starch derivatives as tablet coatings affording gastro-protection. Carboxymethyl starch (CMS) films were obtained by casting of aqueous filmogenic starch solutions with or without plasticizers and their structural organization was followed using Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA), X-ray diffraction (XRD). Together with data from mechanical tests (tensile strength, elongation, Young's modulus) the results were used to select filmogenic formulations adapted for coatings of tablets. The behaviour of these films was evaluated in simulated gastric and intestinal fluids. The effect of plasticizers (glycerol and sorbitol) on the starch organization, on the rate of drying of the films and on the water vapor absorption was also analyzed. Various types of starch have been compared and the best results were found with high amylose starch (HAS) that was carboxymethylated in an aqueous phase to obtain carboxymethyl high amylose starch (CMHAS). The CMHAS coating solutions containing sorbitol or glycerol as plasticizers have been applied with an industrial pan coater and the final tablets exhibited a good gastro-resistance (up to 2h) in simulated gastric fluid followed by disintegration in simulated intestinal fluid (SIF). The CMHAS derivatives present a high potential as coatings for nutraceutical and pharmaceutical solid dosage forms.

Functionalization Methods of Starch and Its Derivatives: From Old Limitations to New Possibilities

It has long been known that starch as a raw material is of strategic importance for meeting primarily the nutritional needs of people around the world. Year by year, the demand not only for traditional but also for functional food based on starch and its derivatives is growing. Problems with the availability of petrochemical raw materials, as well as environmental problems with the recycling of post-production waste, make non-food industries also increasingly interested in this biopolymer. Its supporters will point out countless advantages such as wide availability, renewability, and biodegradability. Opponents, in turn, will argue that they will not balance the problems with its processing and storage and poor functional properties. Hence, the race to find new methods to improve starch properties towards multifunctionality is still ongoing. For these reasons, in the presented review, referring to the structure and physicochemical properties of starch, attempts were made to highlight not only the current limitations in its processing but also new possibilities. Attention was paid to progress in the non-selective and selective functionalization of starch to obtain materials with the greatest application potential in the food (resistant starch, dextrins, and maltodextrins) and/or in the non-food industries (hydrophobic and oxidized starch).

Biodegradable Nanocomposites Based on Blends of Poly(Butylene Adipate-Co-Terephthalate) (PBAT) and Thermoplastic Starch Filled with Montmorillonite (MMT): Physico-Mechanical Properties

Poly(butylene adipate-co-terephthalate) (PBAT) is widely used for production of biodegradable films due to its high elongation, excellent flexibility, and good processability properties. An effective way to develop more accessible PBAT-based bioplastics for wide application in packaging is blending of PBAT with thermoplastic starch (TPS) since PBAT is costly with prices approximately double or even triple the prices of traditional plastics like polyethylene. This study is focused on investigating the influence of TPS/PBAT blend ratio and montmorillonite (MMT) content on the physical and mechanical properties and molecular mobility of TPS-MMT/PBAT nanocomposites. Obtained TPS-MMT/PBAT nanocomposites through the melt blending process were characterized using tensile testing, dynamic mechanical thermal analysis (DMTA), and X-ray diffraction (XRD), as well as solid-state 1H and 13C NMR spectroscopy. Mechanical properties demonstrated that the addition of TPS to PBAT leads to a substantial decrease in the tensile strength as well as in the elongation at break, while Young's modulus is rising substantially, while the effect of the MMT addition is almost negligible on the tensile stress of the blends. DMTA results confirmed the formation of TPS domains in the PBAT matrix. With increasing TPS content, mobility of starch-rich regions of TPS domains slightly increases. However, molecular mobility in glycerol-rich regions of TPS domains in the blends was slightly restricted. Moreover, the data obtained from 13C CP/MAS NMR spectra indicated that the presence of TPS in the sample decreases the mobility of the PBAT chains, mainly those located at the TPS/PBAT interfaces.

Development of Antibacterial Thermoplastic Starch with Natural Oils and Extracts: Structural, Mechanical and Thermal Properties

In this study, the influence of the incorporation of eucalyptus (EO), tea tree (TT) and rosemary (RO) essential oils and Chiriyuyo extract (CE) on the structure and properties of thermoplastic starch (TPS) obtained from potato starch, glycerin and water was evaluated. All oils and the extract were used at a concentration of 0.5 g/100 g of TPS, while for TT, the effect of the concentration was also studied. The mixtures obtained were processed by extrusion and thermocompression molding. The sheets were characterized by XRD, FTIR, TGA, SEM and analyses of their mechanical properties, antimicrobial characteristics and biodegradability. The results show that the use of small concentrations of the oils in 70TPS does not induce changes in the TPS structure according to the results of XRD, FTIR and TGA, with each essential oil and CE affecting the mechanical properties unevenly, although in all cases, antimicrobial activity was obtained, and the biodegradability of TPS in soil was not modified. An increase in the concentration of TT in 60TPS causes marked changes in the crystallinity of TPS, providing a greater modulus with a higher concentration of TT. Regardless of the amount of TT, all sheets maintain antimicrobial characteristics, and their biodegradation in soil is delayed with a higher oil content.

Advancement in Biopolymer Assisted Cancer Theranostics

Applications of nanotechnology have increased the importance of research and nanocarriers, which have revolutionized the method of drug delivery to treat several diseases, including cancer, in the past few years. Cancer, one of the world's fatal diseases, has drawn scientists' attention for its multidrug resistance to various chemotherapeutic drugs. To minimize the side effects of chemotherapeutic agents on healthy cells and to develop technological advancement in drug delivery systems, scientists have developed an alternative approach to delivering chemotherapeutic drugs at the targeted site by integrating it inside the nanocarriers like synthetic polymers, nanotubes, micelles, dendrimers, magnetic nanoparticles, quantum dots (QDs), lipid nanoparticles, nano-biopolymeric substances, etc., which has shown promising results in both preclinical and clinical trials of cancer management. Besides that, nanocarriers, especially biopolymeric nanoparticles, have received much attention from researchers due to their cost-effectiveness, biodegradability, treatment efficacy, and ability to target drug delivery by crossing the blood-brain barrier. This review emphasizes the fabrication processes, the therapeutic and theragnostic applications, and the importance of different biopolymeric nanocarriers in targeting cancer both in vitro and in vivo, which conclude with the challenges and opportunities of future exploration using biopolymeric nanocarriers in onco-therapy with improved availability and reduced toxicity.

Polysaccharide-based nanoassemblies: From synthesis methodologies and industrial applications to future prospects

Polysaccharides, due to their remarkable features, have gained significant prominence in the sustainable production of nanoparticles (NPs). High market demand and minimal production cost, compared to the chemically synthesised NPs, demonstrate a drive towards polysaccharide-based nanoparticles (PSNPs) benign to environment. Various approaches are used for the synthesis of PSNPs including cross-linking, polyelectrolyte complexation, and self-assembly. PSNPs have the potential to replace a wide diversity of chemical-based agents within the food, health, medical and pharmacy sectors. Nevertheless, the considerable challenges associated with optimising the characteristics of PSNPs to meet specific targeting applications are of utmost importance. This review provides a detailed compilation of recent accomplishments in the synthesis of PSNPs, the fundamental principles and critical factors that govern their rational fabrication, as well as various characterisation techniques. Noteworthy, the multiple use of PSNPs in different disciplines such as biomedical, cosmetics agrochemicals, energy storage, water detoxification, and food-related realms, is accounted in detail. Insights into the toxicological impacts of the PSNPs and their possible risks to human health are addressed, and efforts made in terms of PSNPs development and optimising strategies that allow for enhanced delivery are highlighted. Finally, limitations, potential drawbacks, market diffusion, economic viability and future possibilities for PSNPs to achieve widespread commercial use are also discussed.

Effect of Fiber Loading on Thermal Properties of Cellulosic Washingtonia Reinforced HDPE Biocomposites

In this research work, we aim to study the effect of the incorporation of vegetable fiber reinforcement on the thermo-mechanical and dynamic properties of a composite formed by a polymeric matrix reinforced with cellulosic fibers with the various Washingtonia fiber (WF) loadings (0%, 10%, 20%, and 30% by wt%) as reinforced material in high-density polyethylene (HDPE) Biocomposites to evaluate the optimum fiber loading of biocomposites. In addition, several characterization techniques (i.e., thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermal mechanical analysis (TMA)) were used to better understand the characteristics of the new composites prepared. With these techniques, we managed to verify the rigidity and thermal stability of the composites so elaborated, as well as the success of the polymer and the structural homogeneity of the obtained biocomposites. Hence, the biocomposite with the best ratio (HDPE/20WF) showed a loss modulus (E″) of 224 MPa, a storage modulus (E') of 2079 MPa, and a damping factor (Tanδ) of 0.270 to the glass transition (Tg) of 145 °C. In addition, thermomechanical analysis (TMA) of the biocomposite samples exhibited marginally higher Ts compared to the HDPE matrix. The best results were recorded with biocomposites with 20% WF, which showed better thermal properties. This composite material can be used as insulation in construction materials (buildings, false ceilings, walls, etc.).

The Potential Applications of Reinforced Bioplastics in Various Industries: A Review

The introduction of bioplastics has been an evolution for plastic industry since conventional plastics have been claimed to cause several environmental issues. Apart from its biodegradability, one of the advantages can be identified of using bioplastic is that they are produced by renewal resources as the raw materials for synthesis. Nevertheless, bioplastics can be classified into two types, which are biodegradable and non-biodegradable, depending on the type of plastic that is produced. Although some of the bioplastics are non-biodegradable, the usage of biomass in synthesising the bioplastics helps in preserving non-renewable resources, which are petrochemical, in producing conventional plastics. However, the mechanical strength of bioplastic still has room for improvement as compared to conventional plastics, which is believed to limit its application. Ideally, bioplastics need to be reinforced for improving their performance and properties to serve their application. Before 21st century, synthetic reinforcement has been used to reinforce conventional plastic to achieve its desire properties to serve its application, such as glass fiber. Owing to several issues, the trend has been diversified to utilise natural resources as reinforcements. There are several industries that have started to use reinforced bioplastic, and this article focuses on the advantages of using reinforced bioplastic in various industries and its limitations. Therefore, this article aims to study the trend of reinforced bioplastic applications and the potential applications of reinforced bioplastics in various industries.

Research Progress in Hemicellulose-Based Nanocomposite Film as Food Packaging

As the main component of agricultural and forestry biomass, hemicellulose has the advantages of having an abundant source, biodegradability, nontoxicity and good biocompatibility. Its application in food packaging has thus become the focus of efficient utilization of biomass resources. However, due to its special molecular structure and physical and chemical characteristics, the mechanical properties and barrier properties of hemicellulose films are not sufficient, and modification for performance enhancement is still a challenge. In the field of food packaging materials preparation, modification of hemicellulose through blending with nanofibers or nanoparticles, both inorganic and organic, has attracted research attention because this approach offers the advantages of efficient improvement in the expected properties and better cost efficiency. In this paper, the composition of hemicellulose, the classification of nanofillers and the research status of hemicellulose-based nanocomposite films are reviewed. The research progress in modification of hemicellulose by using layered silicate, inorganic nanoparticles and organic nanoparticles in food packaging is described. Challenges and outlook of research in hemicellulose-based nanocomposite film in food packaging is discussed.

An injectable hyperthermic nanofiber mesh with switchable drug release to stimulate chemotherapy potency

We developed a smart nanofiber mesh (SNM) with anticancer abilities as well as injectability and fast recovery from irregular to non-compressible shapes. The mesh can be injected at the tumor site to modulate and control anticancer effects by loading the chemotherapeutic drug, paclitaxel (PTX), as well as magnetic nanoparticles (MNPs). The storage modulus of the mesh decreases when applied with a certain shear strain, and the mesh can pass through a 14-gauge needle. Moreover, the fibrous morphology is maintained even after injection. In heat-generation measurements, the mesh achieved an effective temperature of mild hyperthermia (41-43°C) within 5 min of exposure to alternating magnetic field (AMF) irradiation. An electrospinning method was employed to fabricate the mesh using a copolymer of N-isopropylacrylamide (NIPAAm) and N-hydroxyethyl acrylamide (HMAAm), whose phase transition temperature was adjusted to a mildly hyperthermic temperature range. Pplyvinyl alcohol (PVA) was also incorporated to add shear-thinning property to the interactions between polymer chains derived from hydrogen bonding, The "on-off" switchable release of PTX from the mesh was detected by the drug release test. Approximately 73% of loaded PTX was released from the mesh after eight cycles, whereas only a tiny amount of PTX was released during the cooling phase. Furthermore, hyperthermia combined with chemotherapy after exposure to an AMF showed significantly reduced cancer cell survival compared to the control group. Subsequent investigations have proven that a new injectable local hyperthermia chemotherapy platform could be developed for cancer treatment using this SNM.

Effective Aging Inhibition of the Thermoplastic Corn Starch Films through the Use of Green Hybrid Filler

Recently, hybrid fillers have been widely used to improve the properties of biopolymers. The synergistic effects of the hybrid fillers can have a positive impact on biopolymers, including thermoplastic corn starch film (TPCS). In this communication, we highlight the effectiveness of hybrid fillers in inhibiting the aging process of TPCS. The TPCS, thermoplastic corn starch composite films (TPCS-C), and hybrid thermoplastic corn starch composite film (TPCS-HC) were stored for 3 months to study the effect of hybrid filler on the starch retrogradation. TPCS-C and TPCS-HC were prepared by casting method with 5 wt% of fillers: nanocellulose (NC) and bentonite (BT). The alteration of the mechanical properties, aging behavior, and crystalline structure of the films were analyzed through the tensile test, Fourier transform infrared (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and water absorption analysis. The obtained data were correlated to each other to analyze the retrogradation of the TPCS, which is the main factor that contributes to the aging process of the biopolymer. Results signify that incorporating the hybrid filler (NC + BT) in the TPCS/4BT1NC films has effectively prevented retrogradation of the starch molecules after being stored for 3 months. On the contrary, the virgin TPCS film showed the highest degree of retrogradation resulting in a significant decrement in the film’s flexibility. These findings proved the capability of the green hybrid filler in inhibiting the aging of the TPCS.

Biodegradability, physical, mechanical and antimicrobial attributes of starch nanocomposites containing chitosan nanoparticles

This study aimed to develop a plasticized starch (PS) based film loaded with chitosan nanoparticles (CNPs, 1, 2, 3, and 4%) as a reinforcing and antibacterial agent. We examined the morphology, biodegradability, mechanical, thermo-mechanical, and barrier properties of the PS/CNPs films. The antimicrobial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria was investigated by colony forming unit (CFU) and disc diffusion methods. A dense structure was obtained for all PS/CNPs films and, thus, their complete biodegradation occurred in more days than neat PS. The increase in the CNPs percentage led to improved mechanical behaviour and barrier properties. PS-CNPs composite films revealed inhibition zones against both E. coli and S. aureus, with the 100% reduction in CFU against S. aureus. The current study exhibited that PS-CNPs films were more effective in inhibiting bacteria growth than neat PS film, confirming the composite films potential application as antimicrobial food packaging.

Progress in Starch-Based Materials for Food Packaging Applications

The food packaging sector generates large volumes of plastic waste due to the high demand for packaged products with a short shelf-life. Biopolymers such as starch-based materials are a promising alternative to non-renewable resins, offering a sustainable and environmentally friendly food packaging alternative for single-use products. This article provides a chronology of the development of starch-based materials for food packaging. Particular emphasis is placed on the challenges faced in processing these materials using conventional processing techniques for thermoplastics and other emerging techniques such as electrospinning and 3D printing. The improvement of the performance of starch-based materials by blending with other biopolymers, use of micro- and nano-sized reinforcements, and chemical modification of starch is discussed. Finally, an overview of recent developments of these materials in smart food packaging is given.

Cationized high amylose maize starch films reinforced with borax cross-linked nanocellulose

In this study, a novel strategy for modifying nanocellulose (NC) by borax cross-linking was developed, and the obtained borax modified nanocellulose (BNC) was incorporated into cationized high amylose maize starch (CS) films to evaluate the applicability. Cellulose molecules were successfully cross-linked by boron ester bonds, and the original crystal type and basic chemical structure were not changed. Compared with NC, the relative crystallinity of BNC was slightly increased, and the thermal stability was obviously enhanced. Addition of NC and BNC to CS films significantly improved their tensile strength and water resistance. The dispersion of nanocellulose in CS films was effectively improved by borax cross-linking modification. CS/BNC films showed higher mechanical and water resistance properties compared with CS/NC films. Compared with pure CS film, tensile strength of the composite film with 6 wt% BNC increased about 4.0 times, and its water-vapor permeability decreased about 37%. The novel strategy for preparing BNC by using boron ester bonds will provide a potential approach for the development of starch films with desirable properties.

Erythropoietin, as a biological macromolecule in modification of tissue engineered constructs: A review

In recent years, tissue engineering has emerged as a promising approach to address limitations of organ transplantation. The ultimate goal of tissue engineering is to provide scaffolds that closely mimic the physicochemical and biological cues of native tissues' extracellular matrix. In this endeavor, new generation of scaffolds have been designed that utilize the incorporation of signaling molecules in order to improve cell recruitment, enhance angiogenesis, exert healing activities, and increase the engraftment of the scaffolds. Among different signaling molecules, the role of erythropoietin (EPO) in regenerative medicine is increasingly being appreciated. It is a biological macromolecule which can prevent programed cell death, modulate inflammation, induce cell proliferation, and provide tissue protection in different disease models. In this review, we have outlined and critically analyzed different techniques of scaffolds' modification with EPO or EPO-loaded nanoparticles. We have also explored different strategies for the incorporation of EPO into scaffolds. Non-hematopoietic functions of EPO have also been discussed. Finalizing with detailed discussion surrounding the applications, challenges, and future perspectives of EPO-modified scaffolds in regenerative medicine.

Green Nanocomposites Based on Thermoplastic Starch: A Review

The development of bio-based materials has been a consequence of the environmental awareness generated over time. The versatility of native starch is a promising starting point for manufacturing environmentally friendly materials. This work aims to compile information on the advancements in research on thermoplastic starch (TPS) nanocomposites after the addition of mainly these four nanofillers: natural montmorillonite (MMT), organically modified montmorillonite (O-MMT), cellulose nanocrystals (CNC), and cellulose nanofibers (CNF). The analyzed properties of nanocomposites were mechanical, barrier, optical, and degradability. The most important results were that as the nanofiller increases, the TPS modulus and strength increase; however, the elongation decreases. Furthermore, the barrier properties indicate that that the incorporation of nanofillers confers superior hydrophobicity. However, the optical properties (transparency and luminosity) are mostly reduced, and the color variation is more evident with the addition of these fillers. The biodegradability rate increases with these nanocompounds, as demonstrated by the study of the method of burial in the soil. The results of this compilation show that the compatibility, proper dispersion, and distribution of nanofiller through the TPS matrix are critical factors in overcoming the limitations of starch when extending the applications of these biomaterials. TPS nanocomposites are materials with great potential for improvement. Exploring new sources of starch and natural nano-reinforcement could lead to a genuinely eco-friendly material that can replace traditional polymers in applications such as packaging.

On the Use of OPEFB-Derived Microcrystalline Cellulose and Nano-Bentonite for Development of Thermoplastic Starch Hybrid Bio-Composites with Improved Performance

Thermoplastic starch (TPS) hybrid bio-composite films containing microcrystalline cellulose (C) and nano-bentonite (B) as hybrid fillers were studied to replace the conventional non-degradable plastic in packaging applications. Raw oil palm empty fruit bunch (OPEFB) was subjected to chemical treatment and acid hydrolysis to obtain C filler. B filler was ultra-sonicated for better dispersion in the TPS films to improve the filler–matrix interactions. The morphology and structure of fillers were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). TPS hybrid bio-composite films were produced by the casting method with different ratios of B and C fillers. The best ratio of B/C was determined through the data of the tensile test. FTIR analysis proved the molecular interactions between the TPS and the hybrid fillers due to the presence of polar groups in their structure. XRD analysis confirmed the intercalation of the TPS chains between the B inter-platelets as a result of well-developed interactions between the TPS and hybrid fillers. SEM images suggested that more plastic deformation occurred in the fractured surface of the TPS hybrid bio-composite film due to the higher degree of stretching after being subjected to tensile loading. Overall, the results indicate that incorporating the hybrid B/C fillers could tremendously improve the mechanical properties of the films. The best ratio of B/C in the TPS was found to be 4:1, in which the tensile strength (8.52MPa), Young’s modulus (42.0 MPa), elongation at break (116.4%) and tensile toughness of the film were increased by 92%, 146%, 156% and 338%, respectively. The significantly improved strength, modulus, flexibility and toughness of the film indicate the benefits of using the hybrid fillers, since these features are useful for the development of sustainable flexible packaging film.

Polysaccharide nanoparticles: from fabrication to applications

The present review highlights the developments in polysaccharide nanoparticles with a particular focus on applications in biomedicine, cosmetics and food.

Preparation and Properties of Corn Starch/Chitin Composite Films Cross-Linked by Maleic Anhydride

To improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and incorporated into corn starch (CS) matrix. Before blending, maleic anhydride (MA) was introduced as a cross-linker. Composite CS/MA-CH films were obtained by casting-evaporation approach. Mechanical property estimation showed that addition of 0–7 wt % MA-CH improved the tensile strength of starch films from 3.89 MPa to 9.32 MPa. Elongation at break of the films decreased with the addition of MA-CH, but the decrease was obviously reduced than previous studies. Morphology analysis revealed that MA-CH homogeneously dispersed in starch matrix and no cracks were found in the CS/MA-CH films. Incorporation of MA-CH decreased the water vapor permeability of starch films. The water uptake of the films was reduced when the dosage of MA-CH was below 5 wt %. Water contact angles of the starch films increased from 22° to 86° with 9 wt % MA-CH incorporation. Besides, the composite films showed better inhibition effect against Escherichia coli and Staphylococcus aureus than pure starch films.

Citric-acid modified banana starch nanoparticles as a novel vehicle for β-carotene delivery

BACKGROUND

Starch nanoparticles have become among the most interesting nanovehicles for drug delivery because of their relatively easy synthesis, biocompatibility, and numerous botanical sources. Starch nanoparticles obtained from green bananas were cross-linked with citric acid and loaded with β-carotene.

RESULTS

Mean particle size, encapsulation efficiency, and β-carotene release in simulated gastric and intestinal fluids and food simulants were studied. Cross-linked nanoparticles showed higher loading efficiency and encapsulation capacity, indicating that they can accommodate more molecules than their unmodified counterparts, while mathematical models showed a diffusion of released β-carotene into food simulant media.

CONCLUSIONS

Cross-linked nanoparticles showed more controlled release under gastric conditions, mainly in the simulated intestinal fluid, indicating that they are suitable as vehicles for intestine-specific targeting. This controlled released was also observed in food simulants, with lower release values in the more aqueous simulants. © 2019 Society of Chemical Industry.

On the Use of Starch in Emulsion Polymerizations

The substitution of petroleum-based synthetic polymers in latex formulations with sustainable and/or bio-based sources has increasingly been a focus of both academic and industrial research. Emulsion polymerization already provides a more sustainable way to produce polymers for coatings and adhesives, because it is a water-based process. It can be made even more attractive as a green alternative with the addition of starch, a renewable material that has proven to be extremely useful as a filler, stabilizer, property modifier and macromer. This work provides a critical review of attempts to modify and incorporate various types of starch in emulsion polymerizations. This review focusses on the method of initiation, grafting mechanisms, starch feeding strategies and the characterization methods. It provides a needed guide for those looking to modify starch in an emulsion polymerization to achieve a target grafting performance or to incorporate starch in latex formulations for the replacement of synthetic polymers.