Jackfruit peel cellulose nanocrystal - Alginate hydrogel for doripenem adsorption and release study.

As a natural raw material to replace synthetic chemicals, cellulose and its derivatives are the most popular choices in the pharmaceutical industry. For drug delivery applications, cellulose is usually used as a cellulose nanocrystal (CNC). CNC-based hydrogels are widely utilized for drug delivery because drug molecules can be encapsulated in their pore-like structures. This study aims to develop CNC hydrogels for the delivery of doripenem antibiotics. CNC was obtained from jackfruit peel extraction, and alginate was used as a network polymer to produce hydrogels. Ionotropic gelation was used in the synthesis of CNC-alginate hydrogel composites. The maximum adsorption of doripenem by CNC was 65.7 mg/g, while the maximum adsorption by CNC-alginate was 98.4 mg/g. One of the most challenging aspects of drug delivery is predicting drug release from a solid matrix using simple and complex mathematical equations. The sigmoidal equation could represent the doripenem release from CNC, while the Ritger-Peppas equation could describe the doripenem release from CNC-Alginate. The biocompatibility testing of CNC and CNC-alginate against a 7F2 cell line indicates that both materials were non-toxic.

Polysaccharides gums in drug delivery systems: A review.

For the drug delivery system, drug carriers' selection is critical to the drug's success in reaching the desired target. Drug carriers from natural biopolymers are preferred over synthetic materials due to their biocompatibility. The use of polysaccharide gums in the drug delivery system has received considerable attention in recent years. Polysaccharide gums are renewable resources and abundantly found in nature. They could be isolated from marine algae, microorganisms, and higher plants. In terms of carbohydrates, the gums are water-soluble, non-starch polysaccharides with high commercial value. Polysaccharide gums are widely used for controlled-release products, capsules, medicinal binders, wound healing agents, capsules, and tablet excipients. One of the essential applications of polysaccharide gum is drug delivery systems. The various kinds of polysaccharide gums obtained from different plants, marine algae, and microorganisms for the drug delivery system application are discussed comprehensively in this review paper.

Isotherm data for adsorption of amoxicillin, ampicillin, and doripenem onto bentonite.

The dataset reported in this article describes the adsorption isotherms of amoxicillin, ampicillin, and doripenem onto bentonite. Batch adsorption experiments were carried out on single antibiotic solutions with various dosage of bentonite across temperatures from 30 to 50 °C. The adsorbent loading dataset was later obtained by measuring the concentration of antibiotic solution at adsorption equilibrium via UV-Vis spectrophotometer. The dataset was also fitted using various isotherm models including Freundlich, Langmuir, Toth, Hill, and Dubinin-Radushkevich models to further analyze the adsorption behavior. On top of that, orthogonal regression was applied to avoid fitting biasness, whereby the fitting results revealed the highest adsorption capacities of 82.259 mg g-1 for amoxicillin, 78.851 mg g-1 for ampicillin, and 93.278 mg g-1 for doripenem using Langmuir model, which gave an accurate representation of the adsorption isotherm dataset that was consistent with the results of Toth and Hill model.

Preparation of MIL100/MIL101-alginate composite beads for selective phosphate removal from aqueous solution.

Numerous studies have reported various approaches for synthesizing phosphate-capturing adsorbents to mitigate eutrophication. Despite the efforts, concerns about production cost, the complexity of synthesis steps, environmental friendliness, and applicability in industrial settings continue to be a problem. Herein, phosphate-selective composite adsorbents were prepared by incorporating alginate (Alg) with MIL100 and MIL101 to produce the MIL100/Alg and MIL101/Alg beads, where Fe3+ served as the crosslinker. The unsaturated coordination bond of MIL100 and MIL101 serves as a Lewis acid that can attract phosphate. The adsorption equilibrium isotherm, uptake kinetics, and effects of operating parameters were studied. The phosphate adsorption capacity of MIL100/Alg (103.3 mg P/g) and MIL101/Alg (109.5 mg P/g) outperformed their constituting components at pH 6 and 30 °C. Detailed evaluation of the adsorbent porosity using N2 sorption reveals the formation of mesoporous structures on the Alg network upon incorporation of MIL100 and MIL101. The composite adsorbents have excellent selectivity toward anionic phosphate and can be easily regenerated. Phosphate adsorption by MIL100/Alg and MIL101/Alg was driven by electrostatic attraction and ligand exchange. Preliminary economic analysis on the synthesis of the adsorbents indicates that the composites, MIL100/Alg and MIL101/Alg, are economically viable adsorbents.

Biocompatible and biodegradable copper-protocatechuic metal-organic frameworks as rifampicin carrier.

Tuberculosis (TB) is a disease caused by the M. tuberculosis bacteria infection and is listed as one of the deadliest diseases to date. Despite the development of antituberculosis drugs, the need for long-term drug consumption and low patient commitment are obstacles to the success of TB treatment. A continuous drug delivery system that has a long-term effect is needed to reduce routine drug consumption intervals, suppress infection, and prevent the emergence of drug-resistant strains of M. tuberculosis. For this reason, biomolecule metal-organic framework (BioMOF) with good biocompatibility, nontoxicity, bioactivity, and high stability are becoming potential drug carriers. This study used a bioactive protocatechuic acid (PCA) as organic linker to prepare copper-based BioMOF Cu-PCA under base-modulated conditions. Detailed crystal analysis by the powder X-ray diffraction demonstrated that the Cu-PCA, with a chemical formula of C14H16O13Cu3, crystalizes as triclinic in space group P1. Comprehensive physicochemical characterizations were provided using FTIR, SEM, XPS, TGA, EA, and N2 sorption. As a drug carrier, Cu-PCA showed a high maximum rifampicin (RIF) drug loading of 443.01 mg/g. Upon resuspension in PBS, the RIF and linkers release profile exhibited two-stage release kinetic profiles, which are well described by the Biphasic Dose Response (BiDoseResp) model. A complete release of these compounds (RIF and PCA) was achieved after ~9 h of mixing in PBS. Cu-PCA and RIF@Cu-PCA possessed antibacterial activity against Escherichia coli, and good biocompatibility is evidenced by the high viability of MH-S mice alveolar macrophage cells upon supplementations.

Low-cost structured alginate-immobilized bentonite beads designed for an effective removal of persistent antibiotics from aqueous solution.

The removal of persistent antibiotics from the water bodies can be quite challenging. The present study deals with the removal of doripenem, one of the most stable and persistent antibiotics, from aqueous solution via adsorption technique using the low-cost structured alginate-immobilized bentonite (Alg@iB) beads which can be easily recovered after the process. Alg@iB possesses a porous interior and higher basal spacing compared with the acid-activated bentonite (iB). Its adsorption/desorption isotherm corresponds to type IV IUPAC classification and H4-type hysteresis loops, implying the presence of slit- or plane-shaped pores. The influences of four independent adsorption parameters, e.g., pH, initial doripenem concentrations (md), temperature (T), and Alg@iB loading (mc), on the removal rate of doripenem (Yd) are investigated. The maximum Yd (95.8% w/w) is obtained at pH = 5, mc = 1.4% w/v, T = 50 °C, and md = 250 mg/l. The study suggests that the adsorption of doripenem is spontaneous and endothermic. Further analysis using the multi-linear intra-particle diffusion (IPD) model indicates that the rate-governing step in this adsorption process is the physical diffusion from the bulk solution to the boundary layer of Alg@iB. However, the mechanism study also considers the chemical hydrogen binding between the hydronium ions of Alg@iB and hydroxyl groups of doripenem as one of the driving forces that promote adsorption. Alg@iB shows good reusability with Yd > 90% w/w up to five adsorption cycles. Based on the study, the Alg@iB beads exhibit excellent affinity to doripenem, indicating that an effective doripenem removal can be achieved using this sorbent material.

TiO2/guar gum hydrogel composite for adsorption and photodegradation of methylene blue.

The development of porous adsorbent materials from renewable resources for water and wastewater treatment has received considerable interest from academia and industry. This work aims to synthesize composite hydrogel from the combination of guar gum (a neutral galactomannan polysaccharide) and TiO2. The TiO2-embedded guar gum hydrogel (TiO2@GGH) was utilized to remove methylene blue through adsorption and photodegradation. The presence of TiO2 particles in the hydrogel matrix (TiO2@GGH) was confirmed by scanning electron microscopy-energy dispersive X-ray and X-ray photoelectron spectroscopy analysis. The mercury intrusion and N2 sorption isotherm indicate the macroporous structure of the TiO2@GGH composite, showing the presence of pore sizes ~420 µm. The dye removal efficiency of the GGH and TiO2@GGH was evaluated in batch mode at ambient temperature under varying pH. The effect of UV radiation on the dye removal efficiency was also assessed. The results demonstrated that the highest dye removal was recorded at pH 10, with the equilibrium condition achieved within 5 h. UV radiation was shown to enhance dye removal. The maximum adsorption capacity of TiO2@GGH is 198.61 mg g-1, while GGH sorbent is 188.53 mg g-1. The results imply that UV radiation gives rise to the photodegradation effect.

Nanocelluloses: Sources, Pretreatment, Isolations, Modification, and Its Application as the Drug Carriers.

The 'Back-to-nature' concept has currently been adopted intensively in various industries, especially the pharmaceutical industry. In the past few decades, the overuse of synthetic chemicals has caused severe damage to the environment and ecosystem. One class of natural materials developed to substitute artificial chemicals in the pharmaceutical industries is the natural polymers, including cellulose and its derivatives. The development of nanocelluloses as nanocarriers in drug delivery systems has reached an advanced stage. Cellulose nanofiber (CNF), nanocrystal cellulose (NCC), and bacterial nanocellulose (BC) are the most common nanocellulose used as nanocarriers in drug delivery systems. Modification and functionalization using various processes and chemicals have been carried out to increase the adsorption and drug delivery performance of nanocellulose. Nanocellulose may be attached to the drug by physical interaction or chemical functionalization for covalent drug binding. Current development of nanocarrier formulations such as surfactant nanocellulose, ultra-lightweight porous materials, hydrogel, polyelectrolytes, and inorganic hybridizations has advanced to enable the construction of stimuli-responsive and specific recognition characteristics. Thus, an opportunity has emerged to develop a new generation of nanocellulose-based carriers that can modulate the drug conveyance for diverse drug characteristics. This review provides insights into selecting appropriate nanocellulose-based hybrid materials and the available modification routes to achieve satisfactory carrier performance and briefly discusses the essential criteria to achieve high-quality nanocellulose.

Efficient One-Step Conversion of a Low-Grade Vegetable Oil to Biodiesel over a Zinc Carboxylate Metal-Organic Framework.

In this study, a metal-organic framework, namely, Zn3(BTC)2 (BTC = 1,3,5-benzenetricaboxylic acid), was solvothermally synthesized and employed as a catalyst for biodiesel production from degummed vegetable oil via a one-step transesterification and esterification reaction. The resulting Zn3(BTC)2 particles exhibit a well-defined triclinic structure with an average size of about 1.2 µm, high specific surface area of 1176 m2/g, and thermal stability up to 300 °C. The response surface methodology-Box-Behnken design (RSM-BBD) was employed to identify the optimal reaction conditions and to model the biodiesel yield in relation to three important parameters, namely, the methanol/oil molar ratio (4:1-8:1), temperature (45-65 °C), and time (1.5-4.5 h). Under the optimized reaction conditions (i.e., 6:1 methanol/oil molar ratio, 65 °C, 4.5 h), the maximum biodiesel yield reached 89.89% in a 1 wt % catalyst, which agreed very well with the quadratic polynomial model's prediction (89.96%). The intrinsic catalytic activity of Zn3(BTC)2, expressed as the turnover frequency, was found to be superior to that of other MOF catalysts applied in the transesterification and esterification reactions. The reusability study showed that the as-synthesized Zn3(BTC)2 catalyst exhibited good stability upon three consecutive reuses without a noticeable decrease in the methyl ester yield (∼4%) and any appreciable metal leaching (<5%). Furthermore, a preliminary technoeconomic analysis showed that the total direct operating cost for the kilogram-scale production of Zn3(BTC)2 is estimated to be US$50, which may sound economically attractive.

Atmospheric cold plasma-assisted pineapple peel waste hydrolysate detoxification for the production of bacterial cellulose.

Toxic compounds in pineapple peel waste hydrolysate (PPWH), namely formic acid, 5-hydroxymethylfurfural (HMF), and furfural, are the major predicament in its utilization as a carbon source for bacterial cellulose (BC) fermentation. A rapid detoxification procedures using atmospheric cold plasma (ACP) technique were employed to reduce the toxic compounds. ACP treatment allows the breakdown of toxic compounds without causing excessive breakdown of sugars. Herein, the performance of two available laboratory ACP reactors for PPWH detoxification was being demonstrated. ACP-reactor-1 (R1) runs on plasma power of 80-200 W with argon (Ar) plasma source, while ACP-reactor-2 (R2) runs at 500-600 W with air plasma source. Treatment in R1, at 200 W for 15 min, results in 74.06%, 51.38%, and 21.81% reduction of furfural, HMF, and formic acid. Treatment in R2 at 600 W gives 45.05%, 32.59%, and 60.41% reductions of furfural, HMF, and formic acid. The BC yield from the fermentation of Komagateibacter xylinus in the R1-treated PPWH, R2-treated PPWH, and untreated-PPWH is 2.82, 3.82, and 2.97 g/L, respectively. The results show that ACP treatment provides a novel detoxified strategy in achieving agricultural waste hydrolysate reuse in fermentation. Furthermore, the results also imply that untreated PPWH can be an inexpensive and sustainable resource for fermentation media supplementation.

Fabrication of cellulose carbamate hydrogel-dressing with rarasaponin surfactant for enhancing adsorption of silver nanoparticles and antibacterial activity.

Bacterial contamination on external wounds is known to be a factor that prevents wound healing and triggers tissue damage. Hydrogel-dressings with antibacterial activity is a useful medical device to avoid this contamination, wherein the antibacterial activity can be provided via incorporation of silver nanoparticles (AgNPs). Contrary to the conventional two-step preparation of an AgNPs-loaded hydrogel (AgNPs@hydrogel), this work aims to establish a new and facile synthesis method employing the adsorption principle. Once AgNO3 adsorbed into active sites of the hydrogels, in situ reductions using NaBH4 was employed to produce AgNPs@hydrogel. The effect of surfactant addition on the AgNO3 loading and the antibacterial activity of the resulting hydrogel dressing was investigated. The outcome of this work indicates that the addition of rarasaponin not only can increase the loading of AgNPs on cellulose carbamate hydrogel (CCH) but also significantly enhance the antibacterial activity of the resulted hydrogel-dressing. Superior to the other studied surfactant, the loading capacity (LC) of AgNPs is found to be 10.15, 9.94, and 7.53 mg/g for CCH modified with rarasaponin, CTAB, and Tween80, respectively. These findings conclude that the addition of surfactant, especially rarasaponin, can effectively improve the loading of AgNPs onto hydrogel-dressing via adsorption and promote the antibacterial activity. Furthermore, the cytotoxic test shows that the hydrogel-dressings have good biocompatibility toward skin fibroblast cells.

Studies on the performance of bentonite and its composite as phosphate adsorbent and phosphate supplementation for plant.

Organo-bentonite (OrB) was prepared by modifying bentonite with chitosan, and natural surfactant extracted from Sapindus rarak fruit. The physical alteration post-modification, performance of phosphates (Pi) adsorption, and possibility as a Pi-supplementation for plants of OrB were assessed and compared to acid-activated bentonite (AAB). The physical alteration due to modification of bentonite was characterized. SEM images were not indicating significant morphology differences between OrB and AAB. Existence of chitosan layers in OrB causes a decrease in basal spacing as characterized using XRD. The BET surface area of OrB was decreased compared to AAB due to pore coverage by chitosan. Adsorption studies reveal that OrB has a higher adsorption capacity towards Pi than AAB, which is 97.608 and 131.685 mg/g at 323 K for AAB and OrB, respectively. The H-shape isotherm curve indicates that chemisorption is dominantly controlling the adsorption. The isotherm and kinetics adsorption were well fitted to Langmuir and Pseudo-second order models, respectively. Performance of AAB and OrB as Pi-supplementation was assessed based on growth phenotypes of Arabidopsis thaliana; seedlings show that supplementation of Pi@AAB and Pi@OrB (at half doses) can promote primary root extension. These results also demonstrate the safety of direct disposal of the materials into the soil.

Hydrothermal Synthesize of HF-Free MIL-100(Fe) for Isoniazid-Drug Delivery.

Sustainable development of drug delivery materials with good biocompatibility and controlled-release is a popular topic among researchers. In this research study, we demonstrated the potential of the metal-organic framework, that is MIL-100(Fe), as a drug delivery platform for isoniazid (INH). The MIL-100(Fe) was prepared by using the hydrofluoric acid-free hydrothermal method. Several physical measurements were conducted to characterize the MIL-100(Fe), including x-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen sorption, and thermal-gravimetric (TG). The synthesized MIL-100(Fe) has octahedron-shaped particles with superior properties, that is large surface area (1456.10 m2/g) and pore volume (1.25 cm3/g). The drug loading rate and capacity were determined by means of adsorption kinetic and isotherm. The studied INH@MIL-100(Fe) adsorption system kinetics follow the pseudo-first-order model, while the isotherm system follows the Langmuir model with the maximum adsorption capacity of 128.5 mg/g at 30 °C. MIL-100(Fe) shows adequate biocompatibility, also exhibits a reasonable and controlled drug release kinetics. The results obtained show that MIL-100 (Fe) can be a good choice of drug delivery platform among other available platforms.

Isolation and characterization of starch from Limnophila aromatica.

Starch is one of the digestible natural polymers found in vascular plants. This natural polymer is the primary source of polysaccharides to produce energy for humans. In this work, starch was extracted from the defatted and dephenolated Limnophila aromatica (DFPLA) by using the alkaline method. The DFPLA contains starch with a purity of 70.43 % where 55.1 % of it is the resistant starch. Physicochemical properties of the DFPLA starch such as solubility, morphology, swelling power, crystallinity, gelatinization, retrogradation, decomposition temperature, pasting profile, and surface functional groups were evaluated. The DFPLA starch possesses a medium-amylose content of 23.78 %, and the particle diameters of the starch were varied from 3 to 6 µm. The swelling power and solubility of the DFPLA starch are increasing as the temperature increased, where at 90 °C the swelling power and solubility of the starch is 13.73 g/g and 7.26%, respectively. Starch from DFPLA has a high total dietary fiber (76.28%) which is comparable to that of starch extracted from staple foods. The results indicate that starch from DFPLA possesses good physicochemical properties; this alternative starch may have potential application as a new feedstock for food industries.

Highly adsorptive chitosan/saponin-bentonite composite film for removal of methyl orange and Cr(VI).

Robust and simple composite films for the removal of methyl orange (MO) and Cr(VI) have been prepared by combining chitosan, saponin, and bentonite at a specific ratio. There are several composite films (chitosan-saponin-bentonite (CSB)) prepared; among them, the composite films CSB2:3 and CSB1:1 have the highest removal efficiency toward MO and Cr(VI) where the maximum removal is 70.4% (pH 4.80) and 92.3% (pH 5.30), respectively. It was found that different types of adsorbate have different thermodynamic properties of the adsorption process; the adsorption of MO onto CSB2:3, chitosan, and acid-activated bentonite (AAB) proceeded endothermically, while the adsorption of Cr(VI) onto CSB1:1, chitosan, and AAB proceeded exothermically. The parameters of the adsorption were modeled by using isotherm and kinetic equations. The models of Langmuir, Freundlich, Redlich-Peterson, Sips, and Toth were used for fitting the adsorption isotherm data at a temperature of 30, 45, and 60 °C; all of the isotherm models could represent the data well. The result indicates that CSB2:3 has the highest adsorption capacity toward MO with qm of 360.90 mg g-1 at 60 °C; meanwhile, CSB1:1 has the highest adsorption capacity toward Cr(VI) with qm 641.99 mg g-1 at 30 °C. The pseudo-second-order model could represent the adsorption kinetics data better than the pseudo-first-order equation. The adsorption mechanism was proposed, and the thermodynamic properties of the adsorption were also studied.

Rarasaponin-bentonite-activated biochar from durian shells composite for removal of crystal violet and Cr(VI) from aqueous solution.

This paper presents the preparation of composite material and its application for the adsorption of crystal violet and Cr(VI) from aqueous solution onto acid-activated bentonite (AAB) and rarasaponin-bentonite-activated biochar from durian shells composite (RBAB). The influence of initial pH of the solution and the temperature of adsorption on the adsorbents adsorption performance was also studied. Langmuir and Freundlich models could represent the adsorption equilibria equally well. Thermodynamic parameters such as ∆G°, ∆H°, and ∆S° were evaluated based on the adsorption isotherms. The values of ∆G°, ∆H°, and ∆S° for crystal violet adsorption system demonstrate behavior contrary to the Cr(VI) adsorption system. Where crystal violet adsorption is preferred at high temperatures with qmax, value is 518.64 mg/L; while adsorption Cr(VI) is better at low temperature with qmax, value is 106.30 mg/L. Pseudo-first-order and pseudo-second-order kinetic models could represent the kinetic data well.

Adsorption and photocatalytic performance of bentonite-titanium dioxide composites for methylene blue and rhodamine B decoloration.

Bentonite - TiO2 composites were prepared by impregnation of TiO2 and bentonite, followed by microwave irradiation processes. The composites were characterized using FTIR, SEM, XRD, and nitrogen sorption methods. Anatase phase of TiO2 in all composites are observed through XRD diffraction peaks and surface morphology of the composites. The adsorption and photocatalytic capabilities of the composites were tested in liquid phase adsorption of methylene blue and Rhodamine B. The adsorption and photocatalytic degradation experiments were conducted in the presence or absence of UV light irradiation. Langmuir and Freundlich models were employed to correlate the experimental adsorption data, and it was found that Langmuir gave better performance in correlating the experimental data. Modification of Langmuir equation to accommodate photocatalytic degradation process was conducted, and the model could represent the experimental results very well.

Production of glutinous rice flour from broken rice via ultrasonic assisted extraction of amylose.

In this study, a modified aqueous leaching method by complex formation of amylose with glycerol was employed for reducing the amylose content of starch in broken white rice to less than 2%, so that the resulting starch can be classified to that of glutinous rice flour. By employing ultrasonication in alkaline condition, extraction of amylose could be performed by washing at lower temperature in shorter time compared to the existing aqueous leaching method. The effects of glycerol concentration, alkali concentration, ultrasonication and treatment time on the amylose content of the treated starch were systematically investigated. Under optimum condition, amylose content of broken white rice starch can be reduced from 27.27% to 1.43% with a yield of 80.42%. The changes in the physicochemical properties of the rice flour before and after treatment were studied.

Effect of extraction solvent on total phenol content, total flavonoid content, and antioxidant activity of Limnophila aromatica.

Limnophila aromatica is commonly used as a spice and a medicinal herb in Southeast Asia. In this study, water and various concentrations (50%, 75%, and 100%) of methanol, ethanol, and acetone in water were used as solvent in the extraction of L. aromatica. The antioxidant activity, total phenolic content, and total flavonoid content of the freeze-dried L. aromatica extracts were investigated using various in vitro assays. The extract obtained by 100% ethanol showed the highest total antioxidant activity, reducing power and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity. The same extract also exhibited the highest phenolic content (40.5 mg gallic acid equivalent/g of defatted L. aromatica) and the highest flavonoid content (31.11 mg quercetin equivalent/g of defatted L. aromatica). The highest extraction yield was obtained by using 50% aqueous acetone. These results indicate that L. aromatica can be used in dietary applications with a potential to reduce oxidative stress.

Preparation of capacitor's electrode from cassava peel waste.

Cassava peel was used as the precursor for activated carbon-based electrodes which were then prepared by a combination of chemical and physical activation. The surface of the activated carbon was treated with the oxidative chemical agents, 98 wt.% H(2)SO(4), 65 wt.% HNO(3), and 30 wt.% H(2)O(2) solutions. The surface modification had no significant effect on the specific surface area, but greatly influenced the surface chemistry of the carbons. The presence of oxygen-containing groups increased the polarity and hydrophilicity of activated carbon, and thus improved the performance of the activated carbon-based electrode. As a result, the specific capacitance of the HNO(3) modified AC-electrode reached 264.08F/g, an increase of 72.6% compared to the original one. The results indicate that cassava peel waste can potentially be applied as a raw material for the production of low cost-high performance activated carbon electrode materials for Electric Double Layer Capacitors (EDLCs).