The biocompatibility of novel starch-based polymers and composites: in vitro studies

Quantitatively measuring the cytotoxicity of viscous hydrogels with direct cell sampling in a micro scale format "MicroDrop" and its comparison to CCK8

Tissue engineering holds promise for developing therapeutic applications using viscous materials e.g. hydrogels. However, assessing the cytotoxicity of such materials with conventional assays can be challenging due to non-specific interactions. To address this, we optimized a live/dead staining method for quantitative evaluation and compared it with the conventional CCK8 assay. Our MicroDrop method involved seeding droplets containing 5000 cells in 10 µl medium on 12-well plates. After allowing them to adhere for 4 h, various viscous samples were applied to the cells and measurements were conducted using a fluorescence microscope immediately and at daily intervals up to 72 h. A sodium dodecyl sulfate (SDS) dilution series compared the MicroDrop with the CCK8 assay. The findings revealed a cell-type specific pattern for 10 mg/ml hyaluronic acid (HA), wherein MC3T3-E1 cells maintained 95% viability until 72 h, while L929 cells experienced a gradual decline to 17%. 2 mg/ml HA exhibited consistent viability above 90% across all time points and cell lines. Similarly, fibrin demonstrated 90% viability across dilutions and time points, except for undiluted samples showing a decrease from 85% to 20%. Gelatin-methacrylol sustained viability above 70% across all time points at both 5% and 10% concentrations. The comparison of the SDS dilution series between viability (MicroDrop) and metabolic activity (CCK8) assay showed a correlation coefficient of 0.95. The study validates the feasibility of the established assay, providing researchers with an efficient tool for assessing cytotoxicity in viscous materials. Additionally, it holds the potential to yield more precise data on well-known hydrogels.

Starch-derived carbon quantum dots: Unveiling structural insights and photocatalytic potential as a bio-sourced metal-free semiconductor

The optical appeal and sustainability of carbon quantum dots (CQDs) have led to these nanoparticles swiftly gaining attention and emerging as a new, multifunctional class of nanomaterials. This work centers on the hydrothermal preparation of CQDs utilizing starch, an abundant and renewable biopolymer, as the precursor. Extensive characterization via spectroscopy and microscopy techniques revealed that the starch-derived CQDs exhibit a spherical nanoscale morphology averaging a ∼ 4 nm diameter, demonstrating a red-orange photoluminescence emission. Diffuse reflectance spectroscopic analysis verified their semiconductor behavior, with an estimated direct band gap of 4.1 eV comparable to conventional semiconductors. The prepared CQDs demonstrated considerable promise as metal-free, semiconductor photocatalysts for degrading aqueous dye pollutants under UV irradiation. High photodegradation efficiencies of 45.11 %, 62.94 %, and 91.21 % were achieved for Acid Blue 21, Reactive Blue 94, and Reactive TB 133 dyes, respectively. Systematic investigations of critical process parameters like pH, CQDs dosage, dye concentration, and contact time provided vital insights into the photocatalytic mechanism. The bio-sourced CQD nanomaterials offer a sustainable pathway for effective environmental remediation.

Multivapor-Responsive Controlled Actuation of Starch-Based Soft Actuators

Multivapor-responsive biocompatible soft actuators have immense potential for applications in soft robotics and medical technology. We report fast, fully reversible, and multivapor-responsive controlled actuation of a pure cassava-starch-based film. Notably, this starch-based actuator sustains its actuated state for over 60 min with a continuous supply of water vapor. The durability of the film and repeatability of the actuation performance have been established upon subjecting the film to more than 1400 actuation cycles in the presence of water vapor. The starch-based actuators exhibit intriguing antagonistic actuation characteristics when exposed to different solvent vapors. In particular, they bend upward in response to water vapor and downward when exposed to ethanol vapor. This fascinating behavior opens up new possibilities for controlling the magnitude and direction of actuation by manipulating the ratio of water to ethanol in the binary solution. Additionally, the control of the bending axis of the starch-based actuator, when exposed to water vapor, is achieved by imprinting-orientated patterns on the surface of the starch film. The effect of microstructure, postsynthesis annealing, and pH of the starch solution on the actuation performance of the starch film is studied in detail. Our starch-based actuator can lift 10 times its own weight upon exposure to ethanol vapor. It can generate force ∼4.2 mN upon exposure to water vapor. To illustrate the vast potential of our cassava-starch-based actuators, we have showcased various proof-of-concept applications, ranging from biomimicry to crawling robots, locomotion near perspiring human skin, bidirectional electric switches, ventilation in the presence of toxic vapors, and smart lifting systems. These applications significantly broaden the practical uses of these starch-based actuators in the field of soft robotics.

Effects of glass-ceramic produced by the sol-gel route in macrophages recruitment and polarization into bone tissue regeneration

Effective bone substitute biomaterials remain an important challenge in patients with large bone defects. Glass ceramics produced by different synthesis routes may result in changes in the material physicochemical properties and consequently affect the success or failure of the bone healing response. To investigate the differences in the orchestration of the inflammatory and healing process in bone grafting and repair using different glass-ceramic routes production. Thirty male Wistar rats underwent surgical unilateral parietal defects filled with silicate glass-ceramic produced by distinct routes: BS - particulate glass-ceramic produced via the fusion/solidification route, and BG - particulate glass-ceramic produced via the sol-gel route. After 7, 14, and 21 days from biomaterial grafting, parietal bones were removed to be analyzed under H&E and Massons' Trichome staining, and immunohistochemistry for CD206, iNOS, and TGF-β. Our findings demonstrated that the density of lymphocytes and plasma cells was significantly higher in the BS group at 45, and 7 days compared to the BG group, respectively. Furthermore, a significant increase of foreign body giant cells (FBGCs) in the BG group at day 7, compared to BS was found, demonstrating early efficient recruitment of FBGCs against sol-gel-derived glass-ceramic particulate (BS group). According to macrophage profiles, CD206+ macrophages enhanced at the final periods of both groups, being significantly higher at 45 days of BS compared to the BG group. On the other hand, the density of transformation growth factor beta (TGF-β) positive cells on 21 days were the highest in BG, and the lowest in the BS group, demonstrating a differential synergy among groups. Noteworthy, TGF-β+ cells were significantly higher at 21 days of BG compared to the BS group. Glass-ceramic biomaterials can act differently in the biological process of bone remodeling due to their route production, being the sol-gel route more efficient to activate M2 macrophages and specific FBGCs compared to the traditional route. Altogether, these features lead to a better understanding of the effectiveness of inflammatory response for biomaterial degradation and provide new insights for further preclinical and clinical studies involved in bone healing.

Biopolymer-Based Nanogel Approach in Drug Delivery: Basic Concept and Current Developments

Due to their increased surface area, extent of swelling and active substance-loading capacity and flexibility, nanogels made from natural and synthetic polymers have gained significant interest in scientific and industrial areas. In particular, the customized design and implementation of nontoxic, biocompatible, and biodegradable micro/nano carriers makes their usage very feasible for a range of biomedical applications, including drug delivery, tissue engineering, and bioimaging. The design and application methodologies of nanogels are outlined in this review. Additionally, the most recent advancements in nanogel biomedical applications are discussed, with particular emphasis on applications for the delivery of drugs and biomolecules.

Disulfide-Cross-Linked Nanogel-Based Nanoassemblies for Chemotherapeutic Drug Delivery

Although nanoparticle-based chemotherapeutic strategies have gained in popularity, the efficacy of such therapies is still limited in part due to the different nanoparticle sizes needed to best accommodate different parts of the drug delivery pathway. Herein, we describe a nanogel-based nanoassembly based on the entrapment of ultrasmall starch nanoparticles (size 10-40 nm) within disulfide-crosslinked chondroitin sulfate-based nanogels (size 150-250 nm) to address this challenge. Upon exposure of the nanoassembly to the reductive tumor microenvironment, the chondroitin sulfate-based nanogel can degrade to release the doxorubicin-loaded starch nanoparticles in the tumor to facilitate improved intratumoral penetration. CT26 colon carcinoma spheroids could be efficiently penetrated by the nanoassembly (resulting in 1 order of magnitude higher DOX-derived fluorescence inside the spheroid relative to free DOX), while in vivo experiments showed that doxorubicin-loaded nanoassemblies reduced tumor sizes by 6× relative to saline controls and 2× relative to free DOX after 21 days. Together, these data suggest that nanogel-based nanoassemblies are a viable option for improving the efficacy and safety of nanoparticle-based drug delivery vehicles treating cancer.

Preparation of Surgical Thread from a Bioplastic Based on Nopal Mucilage

Currently, natural materials represent a sustainable option for the manufacture of biopolymers with numerous industrial applications and characteristics comparable with synthetic materials. Nopal mucilage (NM) is an excellent natural resource for the synthesis of bioplastics (BPs). In the present research, the fabrication of biopolymers by using NM is addressed. Changes in the plasticizer (sorbitol and cellulose) concentration, in addition to the implementation of two sources of starch (corn starch (CS) and potato starch (PS)) to obtain the surgical thread, were analyzed. The NM extracted was close to 14% with ethanol. During the characterization of the extract, properties such as moisture, humidity, viscosity, and functional groups, among others, were determined. In the CS and PS analysis, different structures of the polymeric chains were observed. BP degradation with different solvents was performed. Additionally, the addition of sorbitol and cellulose for the BP mixtures presenting the highest resistance to solvent degradation and less solubility to water was conducted. The obtained thread had a uniform diameter, good elasticity, and low capillarity compared to other prototypes reported in the literature.

Green Chemistry Principles for Nano- and Micro-Sized Hydrogel Synthesis

The growing demand for drug carriers and green-technology-based tissue engineering materials has enabled the fabrication of different types of micro- and nano-assemblies. Hydrogels are a type of material that have been extensively investigated in recent decades. Their physical and chemical properties, such as hydrophilicity, resemblance to living systems, swelling ability and modifiability, make them suitable to be exploited for many pharmaceutical and bioengineering applications. This review deals with a brief account of green-manufactured hydrogels, their characteristics, preparations, importance in the field of green biomedical technology and their future perspectives. Only hydrogels based on biopolymers, and primarily on polysaccharides, are considered. Particular attention is given to the processes of extracting such biopolymers from natural sources and the various emerging problems for their processing, such as solubility. Hydrogels are catalogued according to the main biopolymer on which they are based and, for each type, the chemical reactions and the processes that enable their assembly are identified. The economic and environmental sustainability of these processes are commented on. The possibility of large-scale processing in the production of the investigated hydrogels are framed in the context of an economy aimed at waste reduction and resource recycling.

Effects of labeling human mesenchymal stem cells with superparamagnetic zinc-nickel ferrite nanoparticles on cellular characteristics and adipogenesis/osteogenesis differentiation

OBJECTIVE

An attractive cell source for stem cell-based therapy are WJ-MSCs. Hence, tracking WJ-MSCs using non-invasive imaging procedures (such as MRI) and contrast agents (Zn0.5Ni0.5Fe2O4, NFNPs) are required to evaluate cell distribution, migration, and differentiation.

RESULTS

Results showed that the bare and dextrin-coated NFNPs were internalized inside the WJ-MSCs and had no effect on the cell viability, proliferation, apoptosis, karyotyping, and morphology of WJ-MSCs up to 125 µg/mL. Besides, treated WJ-MSCs were differentiated into osteo/adipocyte-like cells. The expression of RUNX 2, SPP 1 (P < 0.05), and OCN (P > 0.05) genes in the WJ-MSCs treated with dextrin-coated NFNPs was higher than the untreated WJ-MSCs; and the expression of CFD, LPL, and PPAR-γ genes was reduced in WJ-MSCs treated with both NFNPs in comparison with the untreated WJ-MSCs (P > 0.05).

CONCLUSION

Overall, results showed that dextrin-coated NFNPs had no adverse effect on the cellular characteristics, proliferation, and differentiation of WJ-MSCs, and suggesting their potential clinical efficacy.

Rice starch coated iron oxide nanoparticles: A theranostic probe for photoacoustic imaging-guided photothermal cancer therapy

In recent years, suitable bioactive materials coated nanoparticles have attracted substantial attention in the field of biomedical applications. The present study emphasizes experimental details for the synthesis of boiling rice starch extract (BRE) coated iron oxide nanoparticles (IONPs) to treat cancer by photoacoustic imaging (PAI)-guided chemo-photothermal therapy. The solvothermal method was used to synthesize IONPs. The physical immobilization method helps to coat BRE-loaded doxorubicin (DOX) molecules on the iron oxide surface. In vitro drug release was estimated in basic (pH 9.0), neutral (pH 7.2), and acidic (pH 4.5) media for varying time periods using ultraviolet-visible spectroscopy. The chemical and physical properties of the synthesized spherical BRE-IONPs were characterized using sophisticated analytical instrumentation. A magnetic saturation experiment was performed with BRE-IONPs for evaluating possible hyperthermia in targeted drug delivery. The biological activity of the synthesized BRE-IONPs was investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and acridine orange/propidium iodide fluorescence cell viability study. BRE-IONPs showed excellent photothermal stability, with a high photothermal conversion efficiency (η = 29.73%), biocompatible property, and high near-infrared region absorption for PAI-guided PTT treatment. This study will provide a better understanding of rice starch as a suitable bioactive coating material for possible theranostic applications.

Facile fabrication of phospholipid-functionalized nanofiber-based barriers with enhanced anti-adhesion efficiency

Electrospun nanofibrous membranes (NFMs) have attracted considerable attention as a potential physical barrier for reducing postoperative adhesion. However, no anti-adhesion barrier can completely prevent adhesion formation. In this study, phospholipid-functionalized NFMs were readily fabricated by one-step electrospinning to obtain nanofiber-based barriers with enhanced wettability and anti-adhesion efficiency. The optimized phospholipid NFMs were shown to have a fiber diameter of 831 nm ± 135 nm that is drastically decreasing, high porosity of 87.6 % ± 1.1 %, and superior hydrophilicity. Moreover, the phospholipid NFMs with excellent cytocompatibility exhibited fibroblasts being significantly reduced (≈ 51 %) after incubation of 3 days compared to that of the NFMs (≈ 96 %), confirming long-lasting anti-adhesion capability against fibroblasts. Meanwhile, less cell adhesion and proliferation of Raw 264.7 macrophages on NFM-10Lec indicated its superior anti-inflammatory effects. Thus, the facile phospholipid-functionalized nanofibers provided a promising strategy for anti-adhesion applications.

A dissolving and glucose-responsive insulin-releasing microneedle patch for type 1 diabetes therapy

A dissolving microneedle patch for responsive insulin release and type 1 diabetes therapy.

Amorphous silibinin nanoparticles loaded into porous starch to enhance remarkably its solubility and bioavailability in vivo

In the present study, the silibinin (SLB) was loaded into porous starch (PS) in the form of nanoparticles (SNPS) by the liquid antisolvent precipitation (LAP) method, so as to improve its solubility and bioavailability. Firstly, the different experimental parameters on drug loading (DL) of the SLB in the LAP process were optimized through the single-factor experiments. Under the optimum conditions, the DL and the encapsulation efficiency (EE) of the SNPS were 9.49 ± 0.37 % and 89.93 ± 0.64 %, respectively. Compared with free SLB and SLB nanoparticles (SN), the SNPS had a higher solubility, and was about 180.81 ± 5.32 μg/mL in artificial gastric juice (AGJ) and was about 88.91 ± 4.14 μg/mL in artificial intestinal juice (AIJ), respectively. The in vitro release study demonstrated a slow and sustained ± release of SLB from the SNPS with the SN and free SLB as controls. The pharmacokinetic results showed that the Cmax and AUC(0-t) of the SNPS (87.71 ± 7.24 μg/L, 439.55 ± 8.76 μg/L*h) increased when compared with the SN (60.31 ± 8.98 μg/L, 206.51 ± 12.24 μg/L*h) and free SLB (26.08 ± 1.43 μg/L, 102.63 ± 7.15 μg/L*h), showing its ability to improve SLB's pharmacokinetic properties.

A Review on Thermoplastic or Thermosetting Polymeric Matrices Used in Polymeric Composites Manufactured with Banana Fibers from the Pseudostem

Recent manufacturing advancements have led to the fabrication of polymeric composites (PC) reinforced with fibers. However, to reduce the impact on the environment, efforts have been made to replace synthetic fibers (SF) by natural fibers (NF) in many applications. NF, e.g., as banana fibers (BF) possess higher cellulose content, a higher degree of polymerization of cellulose, and a lower microfibrillar angle (MFA), which are crucial factors for the mechanical properties (MP), namely tensile modulus (TM) and tensile strength (TS), and many other properties that make them suitable for the reinforcement of PC. This review paper presents an attempt to highlight some recent findings on the MP of PC reinforced with unmodified or modified BF (UBF, MBF), which were incorporated into unmodified or modified (synthetic (SPM) or a bio (BPM)) polymeric matrices (UPM, MPM). The experimental results from previous studies are presented in terms of the variation in the percentage of the MP and show that BF can improve the MP of PC. The results of such studies suggest the possibility to extend the application of PC reinforced with BF (PCBF) in a wide range, namely from automotive to biomedical fields. The meanings of all the acronyms are listed in the abbreviations section.

A Review on Thermoplastic or Thermosetting Polymeric Matrices Used in Polymeric Composites Manufactured with Banana Fibers from the Pseudostem

Recent manufacturing advancements have led to the fabrication of polymeric composites (PC) reinforced with fibers. However, to reduce the impact on the environment, efforts have been made to replace synthetic fibers (SF) by natural fibers (NF) in many applications. NF, e.g., as banana fibers (BF) possess higher cellulose content, a higher degree of polymerization of cellulose, and a lower microfibrillar angle (MFA), which are crucial factors for the mechanical properties (MP), namely tensile modulus (TM) and tensile strength (TS), and many other properties that make them suitable for the reinforcement of PC. This review paper presents an attempt to highlight some recent findings on the MP of PC reinforced with unmodified or modified BF (UBF, MBF), which were incorporated into unmodified or modified (synthetic (SPM) or a bio (BPM)) polymeric matrices (UPM, MPM). The experimental results from previous studies are presented in terms of the variation in the percentage of the MP and show that BF can improve the MP of PC. The results of such studies suggest the possibility to extend the application of PC reinforced with BF (PCBF) in a wide range, namely from automotive to biomedical fields. The meanings of all the acronyms are listed in the abbreviations section.

In-vivo performance of plasma-sprayed CaO-MgO-SiO2-based bioactive glass-ceramic coating on Ti-6Al-4V alloy for bone regeneration

The CaO-MgO-SiO₂-based bioactive glass-ceramic coating (named M2) on Ti-6Al-4V alloy has been proven to behave well in vitro. But how to make full sense of its performances in terms of osteogenesis and osseointegration in vivo matters very much. For this, the M2-coated Ti-6Al-4V cylinders were prepared by atmospheric plasma spraying (APS) and implanted into New Zealand rabbit for 1, 2 and 3 months, respectively, by setting commercial HA-coated Ti-6Al-4V as the control. It is encouraging that, the two groups bonded with the surrounding tissues stably and newly formed bone grew towards or around the implants after 3-month implantation according to radiographic images. From the histological sections, it is obvious that, compared to the control, the M2-coated implant was more favorable for the osteogenesis and neo-vascularisation in the whole experimental process and demonstrated a better osseointegration with the host bone, indicating the former possessed better osteoconductivity, osteoinductivity and osteogenic ability. The study indicated that the M2-coated Ti-6Al-4V implant exerted a great potential to substitute the commercial HA-coated Ti-6Al-4V implant in repairing load-bearing bone defects.

Natural Polysaccharide Nanomaterials: An Overview of Their Immunological Properties

Natural occurring polymers, or biopolymers, represent a huge part of our planet biomass. They are formed by long chains of monomers of the same type or a combination of different ones. Polysaccharides are biopolymers characterized by complex secondary structures performing several roles in plants, animals, and microorganisms. Because of their versatility and biodegradability, some of them are extensively used for packaging, food, pharmaceutical, and biomedical industries as sustainable and renewable materials. In the recent years, their manipulation at the nanometric scale enormously increased the range of potential applications, boosting an interdisciplinary research attempt to exploit all the potential advantages of nanostructured polysaccharides. Biomedical investigation mainly focused on nano-objects aimed at drug delivery, tissue repair, and vaccine adjuvants. The achievement of all these applications requires the deep knowledge of polysaccharide nanomaterials' interactions with the immune system, which orchestrates the biological response to any foreign substance entering the body. In the present manuscript we focused on natural polysaccharides of high commercial importance, namely, starch, cellulose, chitin, and its deacetylated form chitosan, as well as the seaweed-derived carrageenan and alginate. We reviewed the available information on their biocompatibility, highlighting the importance of their physicochemical feature at the nanoscale for the modulation of the immune system.

Rheological characterization of starch gels: A biomass based sorbent for removal of polycyclic aromatic hydrocarbons (PAHs)

Environmental awareness increased the demand for the biomass based materials with superior properties instead of petroleum products. This study aims to prepare starch networks as sorbents for the removal of polycyclic aromatic hydrocarbons (PAHs). Two types of crosslinker, epichlorohydrine (ECH) and glutaraldehyde (GA), were choosed for the preparation of Gel-E and Gel-G networks, respectively. Rheological, swelling and morphological properties of the resulted materials were investigated as a function of various reaction parameters as starch, crosslinker and base concentration and also reaction temperature. The rheological measurements showed that while network formation of Gel-E hydrogels was strongly affected by the NaOH and starch concentration, the strength of the Gel-G hydrogels mainly depends on the crosslinker amount. Starch networks showed high PAH sorption capacities up to 1.42 g per gram sorbent with three model PAH molecules. Although PAH sorption capacities of the Gel-E networks are higher than those of Gel-G gels due to the pore sizes differences of the gel samples, both of them are promising materials as biosorbent for the PAH sorption applications due to the relatively high sorption capacities, low cost and simple preparation methods.

Green Bioplastics as Part of a Circular Bioeconomy

The rapid accumulation of plastic waste is driving international demand for renewable plastics with superior qualities (e.g., full biodegradability to CO₂ without harmful byproducts), as part of an expanding circular bioeconomy. Higher plants, microalgae, and cyanobacteria can drive solar-driven processes for the production of feedstocks that can be used to produce a wide variety of biodegradable plastics, as well as bioplastic-based infrastructure that can act as a long-term carbon sink. The plastic types produced, their chemical synthesis, scaled-up biorefinery concepts (e.g., plant-based methane-to-bioplastic production and co-product streams), bioplastic properties, and uses are summarized, together with the current regulatory framework and the key barriers and opportunities.

Sterile and Dual-Porous Aerogels Scaffolds Obtained through a Multistep Supercritical CO₂-Based Approach

Aerogels from natural polymers are endowed with attractive textural and biological properties for biomedical applications due to their high open mesoporosity, low density, and reduced toxicity. Nevertheless, the lack of macroporosity in the aerogel structure and of a sterilization method suitable for these materials restrict their use for regenerative medicine purposes and prompt the research on getting ready-to-implant dual (macro + meso)porous aerogels. In this work, zein, a family of proteins present in materials for tissue engineering, was evaluated as a sacrificial porogen to obtain macroporous starch aerogels. This approach was particularly advantageous since it could be integrated in the conventional aerogel processing method without extra leaching steps. Physicochemical, morphological, and mechanical characterization were performed to study the effect of porogen zein at various proportions (0:1, 1:2, and 1:1 zein:starch weight ratio) on the properties of the obtained starch-based aerogels. From a forward-looking perspective for its clinical application, a supercritical CO₂ sterilization treatment was implemented for these aerogels. The sterilization efficacy and the influence of the treatment on the aerogel final properties were evaluated mainly in terms of absence of microbial growth, cytocompatibility, as well as physicochemical, structural, and mechanical modifications.

Starch nanoparticles for delivery of the histone deacetylase inhibitor CG-1521 in breast cancer treatment

Background

The efficacy of epigenetic drugs, such as histone deacetylase inhibitors, is often diminished by poor aqueous solubility resulting in limited bioavailability and a low therapeutic index. To overcome the suboptimal therapeutic index, we have developed a biocompatible starch nanoparticle formulation of CG-1521, a histone deacetylase inhibitor in preclinical development for hard-to-treat breast cancers, which improves its bioavailability and half-life.

Methods

The physicochemical parameters (size, zeta potential, morphology, loading, and release kinetics) of these nanoparticles (CG-NPs) have been optimized and their cytotoxic and apoptotic capacities measured in MCF-7 breast cancer cell line. The mechanism of action of the encapsulated drug was compared with the free drug at molecular level.

Results

We show that encapsulation of CG-1521 substantially reduces the release rate of drug and provides a significantly enhanced cytotoxic ability of nanoparticles compared with equivalent dose of free CG-1521. CG-NPs induced cell cycle arrest and significant apoptosis in MCF-7 cells in vitro. The biological action of encapsulated drug has the similar impact with free drug on gene expression.

Conclusion

The findings suggest that encapsulation of CG-1521 into starch nanoparticles can improve drug delivery of histone deacetylase inhibitors for breast cancer therapy without interfering with the mechanism of action of the drug.

Recent advancements in biopolymer and metal nanoparticle-based materials in diabetic wound healing management

Currently, diabetes mellitus (DM) accelerated diabetic foot ulcer (DFU) remains vivacious health problem related with delayed healing and high amputation rates which leads to enormous clinical obligation. Keeping in view of the foregoing, researchers have been made in their efforts to develop novel materials which accelerate delayed wound healing in the diabetic patient and reduce the adversative influences of DFUs. The most prominent materials used for the wound healing application have biocompatibility, low cytotoxicity, excellent biodegradable properties, and antimicrobial activity properties. Utilization of nanoparticles has emerged as a protruding scientific and technological revolution in controlling DFUs. Biopolymers in combination with bioactive nanoparticles having antimicrobial, antibacterial, and anti-inflammatory properties have great potential in wound care to enhance the healing process of diabetic wound infectious. Combination of antibacterial nanoparticles like silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), copper nanoparticles (CuNPs) etc. with polymeric matrix could efficiently inhibit bacterial growth and at the same time fastens the healing process of a wound. This review briefed the recent development of different natural polymers and antibacterial nanoparticles to mitigate the diabetes mellitus based DFU.

Effects of Dendrimer-Like Biopolymers on Physical Stability of Amorphous Solid Dispersions and Drug Permeability Across Caco-2 Cell Monolayers

The potential applications of dendrimer-like biopolymers (DLB) as stabilizing excipients for amorphous solid dispersion (ASD) of niclosamide, celecoxib, and resveratrol were evaluated based on (1) the formation and physical stability of the ASD and (2) the permeability and flux of the agents across Caco-2 cell monolayers. The evaluation was made by comparing the performance of prototype phytoglycogen derivatives (DLB1, DLB2, and DLB3) with commonly used polymers such as HPMCAS, PVPVA, and Soluplus®. PXRD was used to confirm the formation of the dispersions and detect crystallinity peaks formed during 2- and 4-week storage at 40°C/75% RH. At concentrations below 2 g/mL, the viability of Caco-2 cells remained above 80% for all DLB samples compared to untreated cells in the MTT assay. Permeability studies revealed a repeating pattern in which an increase in the initial concentration (C₀) was associated with a concomitant decrease in the apparent permeability (P_app) which we theorize is due to differences in drug-polymer interactions. Niclosamide-DLB1 dispersion had the lowest flux due to a significant reduction in P_app. The high increase in the C₀ of celecoxib-DLB2, however, made up for the reduction in the P_app and produced the highest flux values compared to other polymers. Resveratrol-DLB3 had a 5× reduction in P_app, but C₀ increased from 25.8 to 176 μg/mL led to a higher flux compared to the crystalline drug without polymer. Collectively, these results provide a "proof-of-concept" basis to demonstrate that DLB excipients have the ability to increase apparent solubility (Sol_app), most likely due to drug-binding capacity.

Biomimetic porous high-density polyethylene/polyethylene- grafted-maleic anhydride scaffold with improved in vitro cytocompatibility

A major challenge for tissue engineering is to design and to develop a porous biocompatible scaffold, which can mimic the properties of natural tissue. As a first step towards this endeavour, we here demonstrate a distinct methodology in biomimetically synthesized porous high-density polyethylene scaffolds. Co-extrusion approach was adopted, whereby high-density polyethylene was melt mixed with polyethylene oxide to form an immiscible binary blend. Selective dissolution of polyethylene oxide from the biphasic system revealed droplet-matrix-type morphology. An attempt to stabilize such morphology against thermal and shear effects was made by the addition of polyethylene- grafted-maleic anhydride as a compatibilizer. A maximum ultimate tensile strength of 7 MPa and elastic modulus of 370 MPa were displayed by the high-density polyethylene/polyethylene oxide binary blend with 5% maleated polyethylene during uniaxial tensile loading. The cell culture experiments with murine myoblast C2C12 cell line indicated that compared to neat high-density polyethylene and high-density polyethylene/polyethylene oxide, the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride scaffold significantly increased muscle cell attachment and proliferation with distinct elongated threadlike appearance and highly stained nuclei, in vitro. This has been partly attributed to the change in surface wettability property with a reduced contact angle (∼72°) for 5% PE- g-MA blends. These findings suggest that the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride can be treated as a cell growth substrate in bioengineering applications.

Preparation and Properties of Novel Thermoplastic Vulcanizate Based on Bio-Based Polyester/Polylactic Acid, and Its Application in 3D Printing

Thermoplastic vulcanizate (TPV) combines the high elasticity of elastomers and excellent processability of thermoplastics. Novel bio-based TPV based on poly (lactide) (PLA) and poly (1,4-butanediol/2,3-butanediol/succinate/itaconic acid) (PBBSI) were prepared in this research. PBBSI copolyesters were synthesized by melting polycondensation, and the molecular weights, chemical structures and compositions of the copolyesters were characterized by GPC, NMR and FTIR. Bio-based 2,3-butanediol was successfully incorporated to depress the crystallization behavior of the PBBSI copolyester. With an increase of 2,3-butanediol content, the PBBSI copolyester transformed from a rigid plastic to a soft elastomer. Furthermore, the obtained TPV has good elasticity and rheological properties, which means it can be applied as a 3D-printing material.

Cell viability and hemocompatibility evaluation of a starch-based hydrogel loaded with hydroxyapatite or calcium carbonate for maxillofacial bone regeneration

The objective of this study is to evaluate the cell viability and hemocompatibility of starch-based hydrogels for maxillofacial bone regeneration. Seven starch-based hydrogels were prepared: three loaded with 0.5, 1 and 2% calcium carbonate (Sigma Aldrich, St. Louis, MO, USA); three loaded with 2, 3 and 4% hydroxyapatite (Sigma Aldrich); and one not loaded as a control. A 10 M NaOH was then added to induce hydrogel formation. Human osteoblasts were cultured on each hydrogel for 72 h. An MTS assay (Cell Titer96; PROMEGA, Madison, WI, USA) was used to assess cell viability. Hemocompatibility testing was conducted with normal human blood in the following conditions: 100 mg of each hydrogel in contact with 900 µL of whole blood for 15 min at 37 °C under lateral stirring. Higher percentages of cell viability were observed in starch-based hydrogels loaded with hydroxyapatite as compared with the control. The hemolysis test showed a hemolysis level lower than 2%. Activated partial thromboplastin time and prothrombin time were unchanged, while platelet counting showed a slight decrease when compared with controls.

Equilibrium and kinetics study on removal of arsenate ions from aqueous solution by CTAB/TiO2 and starch/CTAB/TiO2 nanoparticles: a comparative study

We present a comparative study on the efficacy of TiO₂ nanoparticles for arsenate ion removal after modification with CTAB (N-cetyl-N,N,N-trimethyl ammonium bromide) followed by coating with starch biopolymer. The prepared nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), thermogravimetry, scanning electron microscopy (SEM) and electron dispersive X-ray analysis (EDX). The removal efficiency was studied as a function of contact time, material dose and initial As(V) concentration. CTAB-modified TiO₂ showed the highest arsenate ion removal rate (∼99% from 400 μg/L). Starch-coated CTAB-modified TiO₂ was found to be best for regeneration. For a targeted solution of 400 μg/L, a material dose of 2 g/L was found to be sufficient to reduce the As(V) concentration below 10 μg/L. Equilibrium was established within 90 minutes of treatment. The sorption pattern followed a Langmuir monolayer pattern, and the maximum sorption capacity was found to be 1.024 mg/g and 1.423 mg/g after starch coating and after CTAB modification, respectively. The sorption mechanisms were governed by pseudo second order kinetics.

Comparative analysis of stability and biological activities of violacein and starch capped silver nanoparticles

This study highlights the synthesis of starch and violacein capped AgNPs through reducing agents. The violacein capped AgNPs are more stable than starch capped AgNPs and have more potent antimicrobial activities in comparison to starch capped AgNPs.

Modulated in Vitro Biocompatibility of a Unique Cross-Linked Salicylic Acid-Poly(ε-caprolactone)-Based Biodegradable Polymer

Herein, we report the development of a unique architecture by chemically cross-linking salicylic acid (SA)-based poly(anhydride ester) onto a biodegradable amine-functionalized poly(caprolactone) (PCL), using lactic acid as a spacer. The ester and amide linkages in the SA-PCL polymer, synthesized through melt condensation, were confirmed by NMR and FT-IR spectroscopic techniques. The enzymatic and nonenzymatic hydrolytic degradation profile exhibited linear degradation kinetics over an extended time period (>5 weeks). The compatibility and growth of C2C12 myoblast cells were found to be significantly improved on the fast-degrading SA-PCL substrates compared to those over neat PCL and amine-functionalized PCL. Further, the decreased red blood cell damage, illustrated by 0.39% hemolysis activity and a minimal number of platelet adhesion on a SA-PCL polymeric surface confirmed good hemocompatibility of the as-synthesized polymer. Together with a moderate bactericidal property, the spectrum of properties of this novel polymer can be attributed to the synergistic effect of the presence of chemical moieties of SA and amine groups in PCL. In summary, it is considered that a SA-PCL-based cross-linked composite can be utilized as a new biodegradable polymer.