Multifunctional Drug Delivery System Using Starch-Alginate Beads for Controlled Release

Tailored alginate sponges loaded with κ-carrageenan beads for controlled release of curcumin

This study presents an innovative approach to develop and characterize an alginate sponge containing κ-carrageenan (κ-CRG) beads loaded with curcumin. The beads were fabricated using varying concentrations of κ-CRG, and their properties were extensively evaluated using inverted phase-contrast microscopy, Scanning Electron Microscopy (SEM), FTIR, swelling behavior, mass distribution, encapsulation efficiency, in vitro drug release and kinetics of drug release. Beads formulated with specific concentrations of κ-CRG that exhibited optimal performance were then integrated into an alginate sponge matrix, which underwent similar comprehensive testing procedures as the individual beads. The characterized beads displayed a spherical morphology, a notable swelling degree of approximately 146 %, excellent mass uniformity, encapsulation efficiencies higher than 90 % and drug release rate exceeding 70 %. Moreover, the alginate sponge formulation demonstrated a satisfactory drug release profile of 67.9 ± 0.6 %. In terms of drug release kinetics, the Higuchi model was the most effective in explaining the release of curcumin from beads and sponge. These findings underscore the potential of both the beads and the sponge as effective vehicles for the controlled delivery of curcumin, positioning them as promising candidates for pharmaceutical applications across various fields.

Production of Plant-Based, Film-Type Scaffolds Using Alginate and Corn Starch for the Culture of Bovine Myoblasts

Natural scaffolds have been the cornerstone of tissue engineering for decades, providing ideal environments for cell growth within extracellular matrices. Previous studies have favored animal-derived materials, including collagen, gelatin, and laminin, owing to their superior effects in promoting cell attachment, proliferation, and differentiation compared to non-animal scaffolds, and used immortalized cell lines. However, for cultured meat production, non-animal-derived scaffolds with edible cells are preferred. Our study represents the first research to describe plant-derived, film-type scaffolds to overcome limitations associated with previously reported thick, gel-type scaffolds completely devoid of animal-derived materials. This approach has been employed to address the difficulties of fostering bovine muscle cell survival, migration, and differentiation in three-dimensional co-cultures. Primary bovine myoblasts from Bos Taurus Coreanae were harvested and seeded on alginate (Algi) or corn-derived alginate (AlgiC) scaffolds. Scaffold functionalities, including biocompatibility and the promotion of cell proliferation and differentiation, were evaluated using cell viability assays, immunofluorescence staining, and reverse transcription-quantitative polymerase chain reaction. Our results reveal a statistically significant 71.7% decrease in production time using film-type scaffolds relative to that for gel-type scaffolds, which can be maintained for up to 7 days. Film-type scaffolds enhanced initial cell attachment owing to their flatness and thinness relative to gel-type scaffolds. Algi and AlgiC film-type scaffolds both demonstrated low cytotoxicity over seven days of cell culture. Our findings indicated that PAX7 expression increased 16.5-fold in alginate scaffolds and 22.8-fold in AlgiC from day 1 to day 3. Moreover, at the differentiation stage on day 7, MHC expression was elevated 41.8-fold (Algi) and 32.7-fold (AlgiC), providing initial confirmation of the differentiation potential of bovine muscle cells. These findings suggest that both Algi and AlgiC film scaffolds are advantageous for cultured meat production.

Synthesis and Characterization of Calcium Alginate-Based Microspheres Entrapped with TiO2 Nanoparticles and Cinnamon Essential Oil Targeting Clinical Staphylococcus aureus

It is important to create new generations of materials that can destroy multidrug-resistant bacterial strains, which are a serious public health concern. This study focused on the biosynthesis of an essential oil entrapped in titanium dioxide (TiO₂) calcium alginate-based microspheres. In this research, calcium alginate-based microspheres with entrapped TiO₂ nanoparticles and cinnamon essential oil (CI-TiO₂-MSs) were synthesized, using an aqueous extract of Nigella sativa seeds for TiO₂ nanoparticle preparation, and the ionotropic gelation method for microsphere preparation. The microspheres obtained were spherical, uniformly sized, microporous, and rough surfaced, and they were fully loaded with cinnamon essential oil and TiO₂ nanoparticles. The synthesized microspheres were analyzed for antibacterial activity against the clinical multidrug-resistant strain of Staphylococcus aureus. Disc diffusion and flow cytometry analysis revealed strong antibacterial activity by CI-TiO₂-MSs. The synthesized CI-TiO₂-MSs were characterized by the SEM/EDX, X-ray diffraction, and FTIR techniques. Results showed that the TiO₂ nanoparticles were spherical and 99 to 150 nm in size, whereas the CI-TiO₂-MSs were spherical and rough surfaced. Apoptosis analysis and SEM micrography revealed that the CI-TiO₂-MSs had strong bactericidal activity against S. aureus. The in vitro antibacterial experiments proved that the encapsulated CI-TiO₂-MSs had strong potential for use as a prolonged controlled release system against multidrug-resistant clinical S. aureus.

Mechanical properties of starch-filled alginate gel particles

The aim of this work was to investigate the mechanical behaviour of alginate-based composite particles. Alginate gel beads with entrapped starch were used as the replicates of storage cells of plant tissue. Beads were formulated using different ratios of both ingredients and were produced using two methods, resulting in particles in the macro- and micro-scale size range. Compression tests revealed an effect of bead size on mechanical properties and a dominant role of the alginate on the material properties. Starch was successfully encapsulated as native granules in the beads and once encompassed, it suffered restricted swelling, up to 45 % of its original size, after undergoing heating. Force versus displacement data were fitted to both an empirical and the Hertz model and Young's modulus was found to increase only with heated starch inclusions. Microscopy was deemed crucial for the interpretation of mechanical measurements.

Starch modified alginate nanoparticles for drug delivery application

Natural polymers have been widely studied as vehicles that have gained much interest in the encapsulation and delivery of drugs and bioactive molecules. In this study, we developed starch-modified alginate nanoparticles using a green facile technique for drug delivery application. The potential of the prepared nanoparticles for controlled drug delivery applications is demonstrated using theophylline and bovine serum albumin as model drugs. The nanoparticles possessed the encapsulation efficiency of 60 to 75%. The results of in vitro drug release studies showed the pH dependent characteristics of the prepared nanoparticles. In vitro cytotoxicity test revealed the biocompatibility of the developed nanoparticles against L929 fibroblast cell lines. The in vitro cellular uptake of nanoparticles was visualized in L929 fibroblast cells using fluorescent microscopy. The preliminary investigation suggests the developed nanoparticle is a promising candidate for drug delivery application.

Formulation of Microbial Inoculants by Encapsulation in Natural Polysaccharides: Focus on Beneficial Properties of Carrier Additives and Derivatives

In the last 10-15 years, the wide application of bioformulated plant beneficial microorganisms is accepted as an effective alternative of chemical agro-products. Two main problems can be distinguished in their production and application: (a) economical competiveness based on the overall up-stream and down-stream operational costs, and (b) development of commercial products with a high soil-plant colonization potential in controlled conditions but not able to effectively mobilize soil nutrients and/or combat plant pathogens in the field. To solve the above problems, microbe-based formulations produced by immobilization methods are gaining attention as they demonstrate a large number of advantages compared to other solid and liquid formulations. This mini-review summarizes the knowledge of additional compounds that form part of the bioformulations. The additives can exert economical, price-decreasing effects as bulking agents or direct effects improving microbial survival during storage and after introduction into soil with simultaneous beneficial effects on soil and plants. In some studies, combinations of additives are used with a complex impact, which improves the overall characteristics of the final products. Special attention is paid to polysaccharide carriers and their derivates, which play stimulatory role on plants but are less studied. The mini-review also focuses on the potential difficulty in evaluating the effects of complex bio-formulations.

Ultrasonic-assisted fabrication of starch/MWCNT-glucose nanocomposites for drug delivery

The principal focus of this investigation is to prepare starch nanocomposite (NC) films containing multi-walled carbon nanotube (MWCNT) and apply these NCs for drug delivery. Firstly, to raise the hydrophilicity of carboxyl functionalized MWCNT, the surface of them was modified with d-glucose (Gl) as a low cost and environmentally friendly biomolecule. Different percentages of MWCNT-Gl (0.5, 1 and 2wt%) were embedded in starch matrix through sonochemical method as an economical, fast, eco-friendly, and effective method. The properties of starch/MWCNT-Gl NCs were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy and transmission electron microscopy (TEM). Afterwards, pure starch and starch/MWCNT-Gl NCs were reacted with oleic acid to obtain amphiphilic (Amph) esters. Except Amph obtained from pure starch, other Amph esters could convert to drug-loaded nanoparticles which were characterized by dynamic light scattering and TEM. The sizes of nanoparticles depended on the value of MWCNT-Gl. The thinnest particles obtained from starch/MWCNT-Gl NCs containing the highest value of MWCNT-Gl (2wt%), and this system was chosen for measurement of entrapment efficiency, loading capacity and in vitro release study for zolpidem as a hydrophobic drug model.

Surface modification of cotton fabrics for antibacterial application by coating with AgNPs-alginate composite

In recent years nano-sized particles have been focused on bacteriostasis. We investigated antimicrobial activities by applying AgNPs-alginate composite on cotton fabric, using a simple one-step rapid synthetic route by reduction of silver nitrate using alkali hydrolyzed alginate solution which acts as both reducing and capping agent. FTIR spectra, color coordinates, silver content, silver release percent and SEM images of treated fabric samples confirmed the successful physical deposition of AgNPs-alginate composite on the fabric. The treated fabrics demonstrated an excellent antibacterial activity against the tested bacteria, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. A slight decrease in the antibacterial feature of the cotton fabrics was observed after successive washings. However, an efficient antibacterial activity still remained on the fabrics.

Microfluidic synthesis of microfibers for magnetic-responsive controlled drug release and cell culture

This study demonstrated the fabrication of alginate microfibers using a modular microfluidic system for magnetic-responsive controlled drug release and cell culture. A novel two-dimensional fluid-focusing technique with multi-inlets and junctions was used to spatiotemporally control the continuous laminar flow of alginate solutions. The diameter of the manufactured microfibers, which ranged from 211 µm to 364 µm, could be well controlled by changing the flow rate of the continuous phase. While the model drug, diclofenac, was encapsulated into microfibers, the drug release profile exhibited the characteristic of a proper and steady release. Furthermore, the diclofenac release kinetics from the magnetic iron oxide-loaded microfibers could be controlled externally, allowing for a rapid drug release by applying a magnetic force. In addition, the successful culture of glioblastoma multiforme cells in the microfibers demonstrated a good structural integrity and environment to grow cells that could be applied in drug screening for targeting cancer cells. The proposed microfluidic system has the advantages of ease of fabrication, simplicity, and a fast and low-cost process that is capable of generating functional microfibers with the potential for biomedical applications, such as drug controlled release and cell culture.

Formulation and characterization of tramadol-loaded IPN microgels of alginate and gelatin: Optimization using response surface methodology

Tramadol-loaded interpenetrating polymer network (IPN) alginate-gelatin (AG) microgels (MG) were prepared by the chemical cross-linking technique with glutaraldehyde as cross-linking agent and were optimized using response surfaces. A central composite design for 2 factors, at 3 levels each, was employed to evaluate the effect of critical formulation variables, namely the amount of gelatin (X1) and glutaraldehyde (X2), on geometric mean diameter, encapsulation efficiency, diffusion coefficient (D), amount of mucin adsorbed per unit mass (Qe) and 50 % drug release time (t50). Microgels with average particle size in the range of 44.31-102.41 μm were obtained. Drug encapsulation up to 86.5 % was achieved. MGs were characterized by FT-IR spectroscopy to assess formation of the IPN structure and differential scanning calorimetry (DSC) was performed to understand the nature of drug dispersion after encapsulation into IPN microgels. Both equilibrium and dynamic swelling studies were performed in pH 7.4 phosphate buffer. Diffusion coefficients and exponents for water transport were determined using an empirical equation. The mucoadhesive properties of MGs were evaluated in aqueous solution by measuring the mucin adsorbed on MGs. Adsorption isotherms were constructed and fitted with Freundlich and Langmuir equations. In vitro release studies indicated the dependence of drug release on the extent of cross-linking and the amount of gelatin used in preparing IPNs. The release rates were fitted to a power law equation and Higuchi's model to compute the various drug transport parameters, n value ranged from 0.4055 to 0.5754, suggesting that release may vary from Fickian to quasi-Fickian depending upon variation in the formulation composition.

The controlled and sustained release of a fungicide from starch and alginate beads

This paper describes the synthesis of starch and alginate beads as controlled release formulations. Different formulations of the fungicide, thiram, were prepared by using BaCl(2) and AlCl(3) as crosslinkers. The beads thus formed were characterized by FTIR and swelling studies. Formulation characteristics like entrapment efficiency, bead size, percentage equilibrium swelling have been evaluated. The release studies of the fungicide from the beads were carried out in vitro and in soil columns. The beads prepared with AlCl(3) have shown more swelling as well as the fungicide release in comparison to beads prepared with BaCl(2). From the soil column studies it was observed that the release of pesticide from the beads occurred in very controlled and sustained manner.

Multi-unit floating alginate system: effect of additives on ciprofloxacin release

In an attempt to fabricate floating beads of ciprofloxacin, drugloaded alginate beads were prepared by simultaneous external and internal gelation. The effect of blending of alginate with gellan, hydroxypropyl methylcellulose, starch, and chitosan on the bead properties were evaluated. Beads were spherical with incorporation efficiency in the range of 52.81 +/- 2.64 to 78.95 +/- 1.92%. Beads exhibited buoyancy over a period of 7-24 hr based on the formulation variables. In vitro release of ciprofloxacin from the alginate beads in simulated gastric fluid (SGF) (0.1 N HCl, pH 1.2), was influenced significantly (p < 0.001) by the properties and concentration of additives. Among the polymers incorporated into alginate beads. Hydroxy propyl methylcellulose (HPMC) provided an extended release over 7 hr. The drug release predominately followed Higuchi's square root model.

The Impact of Trimethyl Chitosan on In Vitro Mucoadhesive Properties of Pectinate Beads along Different Sections of Gastrointestinal Tract

Pectinate (PEC) beads are multiparticulate dosage forms which have been extensively investigated for oral drug delivery; however their mucoadhesive properties in various sections of GI tract have, not been yet reported. This work evaluated the in vitro mucoadhesive properties of PEC bead formulations, on rat everted gastrointestinal sections, either with or without trimethyl chitosan (TMC), an absorption-enhancing and fairly mucoadhesive derivative of chitosan. Reference Carbomer 934P (C934P) granules, as an established mucoadhesive polymer, and ethyl cellulose (EC)-coated pellets, as a nonmucoadhesive dosage form, were also used for comparison. Water uptake studies were also performed to further explain the effect of hydration on mucoadhesive properties. PEC beads showed mucoadhesion, which was in some cases comparable to C934P granules, towards the gastrointestinal tissues with following ranking: duodenum approximately jejunum approximately ileum > cecum > colon > stomach. In the dry state, the beads containing TMC were more mucoadhesive, while in the moist state simple PEC beads were shown to be more mucoadhesive. Over-hydration of TMC-containing beads may account for this observation. The results of this study suggest that in cases which prehydration can be avoided, such as when the beads are protected in a site-specific oral capsule, prior to reaching the target tissue, the incorporation of TMC into beads might be useful, as a means of increasing the mucoadhesive properties; However, further studies are needed to clarify their in vivo feasibility.

Comparative study of nanohydroxyapatite microspheres for medical applications

This study concerns the preparation, physical, and in vitro characterization of two different types of hydroxyapatite (HA) microspheres, which are intended to be used as drug-delivery systems and bone-regeneration matrices. Hydroxyapatite nanoparticles (HA-1 and HA-2) were prepared using the chemical precipitation synthesis with H(3)PO(4), Ca(OH)(2), and a surfactant, SDS (sodium dodecyl sulfate), as starting reagents. The HA powders were dispersed in a sodium alginate solution, and spherical particles were obtained by droplet extrusion coupled with ionotropic gelation in the presence of Ca(2+). These were subsequently sintered to produce HA-1 and HA-2 microspheres with a uniform size and interconnected microporosity. Both powders and microspheres were characterized using FTIR and X-ray diffraction. Moreover, SEM and mercury intrusion porosimetry were used to analyze the microspheres, and TEM was used to analyze the powders. Results showed that pure HA and mixtures of HA/beta-TCP in the nanometer range and needlelike shape were obtained for HA-1 and HA-2 powders, respectively. Neutral Red, scanning electron microscopy and confocal microscopy were used to evaluate the behavior of osteoblastic-like MG-63 cells cultured on HA microspheres surfaces for 7 days. Results showed that good adhesion and proliferation of osteoblasts on the HA microspheres surface. Cells built bridges between adjacent microspheres, forming microspheres-cells clusters in both types of materials.