Gelation Method Research Articles

Quality by design (QbD) approach-based development of optimized nanocarrier to achieve quality target product profile (QTPP)-targeted lymphatic delivery

Background. Insulin, commonly used for diabetes treatment, needs better ways to improve its effectiveness and safety due to its challenges with poor permeability and stability. Various system has been developed for oral peptide delivery. The non-targeted system can prevent gastric and enzymatic degradation of peptides but cannot increase the bulk transport of peptides across the membrane. However, the non-selectivity is the limitation of the existing system. Numerous carbohydrate-binding receptors overexpressed on intestinal macrophage cells (M-cells) of gut-associated lymphoid tissue. It is the most desirable site for receptor-mediated endocytosis and lymphatic drug delivery of peptides. Objective. The prime objective of the study was to fabricate mannose ligand conjugated nanoparticles (MNPs) employing a quality-by-design approach to address permeability challenges after oral administration. Herein, the study’s secondary objective of this study is to identify the influencing factor for producing quality products. Considering this objective, the Lymphatic uptake of NPs was selected as a quality target product profile (QTPP), and a systematic study was conducted to identify the critical formulation attributes (CFAs) and critical process parameters (CPP) influencing critical quality attributes (CQAs). Mannosylated Chitosan concentrations (MCs) and TPP concentrations were identified as CFAs, and stirring speed was identified as CPP. Methods. MNPs were prepared by the inotropic gelation method and filled into the enteric-coated capsule to protect from acidic environments. The effect of CFAs and CPP on responses like particle size (X) and entrapment (Y) was observed by Box-Behnken design (BBD). ANOVA statistically evaluated the result to confirm a significant level (p < 0.05). The optimal conditions of NPs were obtained by constructing an overlay plot and determining the desirability value. HPLC and zeta-seizer analysis characterized the lyophilized NPs. Cell-line studies were performed to confirm the safety and M-cell targeting of NPs to enhance Insulin oral bioavailability. Results. The morphology of NPs was revealed by SEM. The developed NPs showed a nearly oval shape with the average size, surface potential, and % drug entrapment were 245.52 ± 3.37 nm, 22.12 ± 2.13 mV, and 76.15 ± 1.3%, respectively. MTT assay result exhibited that MNPs safe and Confocal imaging inference that NPs selectively uptake by the M-cell. Conclusion. BBD experimental design enables the effective formulation of optimized NPs. The statistical analysis estimated a clear assessment of the significance of the process and formulation variable. Cell line study confirms that NPs are safe and effectively uptake by the cell.

Effect Of Different Variables On The Formulation Of Sodium Alginate Beads

This work examined the possibility of encapsulating prednisolone as drug modelling in Na-alginate polymeric beads. Our beads were formulated by ionotropic gelation method using Na-alginate as an anionic natural polysaccharide polymer and Cacl2  as a positive charge cross-linker. Eleven formulations were successfully created, and different variations were evaluated, including Na-alginate concentration ( 0.5, 2, 3) w/v %, Cacl2 concentration (1, 3, 5) w/v % stirring speed (100, 300, 400) rpm, the addition of tween-80 (0, 2.5, 5) ml, washing beads with alcohol,  change curing time. The beads were assayed by bead size, morphology, drug loading, encapsulation efficiency, yield and FTIR. The results showed that the best formula was F2 which can be obtained when using a high concentration of Na-alginate (2 w/v %), Cacl2 (5 w/v %), the addition of tween-80 (5ml) with the lowest stirring speed (100 rpm) without increase curing time or washing with alcohol. Also, the FTIR result revealed a shifting of the carbonyl group and a low intensity of the hydroxyl group in the spectrogram of F2, indicating potential hydrogen bond interactions that might have resulted in the creation of beads.

Antioxidant properties and effects of formulation variables on &lt;i&gt;Ceiba pentandra&lt;/i&gt; microspheres

Background: New drug delivery techniques have improved therapeutic and physicochemical properties of herbal medicines.Objective: Extracts of Ceiba pentandra (CP) leaf have been evaluated for antioxidant properties with the aim of formulating them into microspheres and studying release of flavonoid from the dosage form.Materials and Methods: Microspheres were prepared from extracts of CP using ionotropic gelation method. Formulation parameters were varied to produce A1 to A8. Microspheres were evaluated for size, shape, yield, micrometrics, swelling, entrapment efficiency, and flavonoid release characteristics. Factorial experimentation design was used to determine the individual and interactive effects of the formulation variables on entrapment efficiency and flavonoid release. Results were analysed using ANOVA at p≤0.05.Results: The extract contained flavonoids. Microspheres were discrete, porous, spherical, with good flow. Microspheres swelled moderately and eroded within 3 hours. Entrapment efficiencies ranged from 4.17 to 19.2 %. All Formulations released 80 % of flavonoid within 6 hours, except A2, A3 and A8 which sustained flavonoid release for 24 – 26 hours. Concentration of polymer had the highest positive effect, while stirring speed had the highest negative effect on microsphere entrapment efficiency. Effect of curing time on entrapment efficiency was positive but insignificant. Polymer concentration and curing time had negative effects on flavonoid release, while stirring speed showed a positive effect.Conclusion: Extracts of Ceiba pentandra leaves possess antioxidant constituents and could be formulated into microspheres of good physicochemical properties. Concentrations of polymer and curing time are important parameters that should be considered in the formulation of CP into microspheres with sustained release potentials.

Chitosan/starch based unoxidized tannic acid modified microparticles for rapid hemostasis with broad spectrum antibacterial activity

The development of a rapid hemostat through a facile method with co-existing antibacterial activity and minimum erythrocyte lysis property stands as a major requirement in the field of hemostasis. Herein, a series of novel microparticle hemostats were synthesized using chitosan, different hydrothermally-treated starches, and cross-linked with tannic acid (TA) simultaneously in an unoxidized environment via ionotropic gelation method. Hemostats' comparative functional properties, such as adjustable antibacterial and erythrocyte compatibility upon various starch additions were evaluated. The in vivo hemostatic study revealed that the developed hemostats for mouse liver laceration and rat tail amputation had clotting times (13 s and 38 s, respectively) and blood loss (51 mg and 62 mg, respectively) similar to those of Celox™. The erythrocyte adhesion test suggested that erythrocyte distortion can be lowered by modifying the antibacterial hemostats with different starches. The broad-spectrum antibacterial efficacy of the hemostats remained intact against S. aureus (>90 %), E. coli (>80 %), and P. mirabilis bacteria upon starch modification. They also demonstrated high hemocompatibility (<3 % hemolysis ratio), moderate cell viability (>81 %), in vivo biodegradation, and angiogenesis indicating adequate biocompatibility and wound healing. The developed hemostats hold significant promise to be employed as rapid hemostatic agents for preventing major bleeding and bacterial infection in emergencies.

Waste cooking oil based capsules for sustainable self-healing asphalt pavement: Encapsulation, characterization and fatigue-healing performance

Waste cooking oil has surfaced as a hazardous waste that induces severe environmental contamination. Encapsulation technology presents a viable solution to regenerate the waste oil and augment the self-healing ability of asphalt materials. This study characterized capsules synthesized with selected waste oil for self-healing asphalt mixture, and evaluated the self-healing and environmental impact. The wetting ability, capillary, anti-aging, and self-healing performance of three potential healing agents were analyzed, and the optimal healing agent was obtained by evaluating the comprehensive behavior with the radar chart method. Capsules were synthesized using the ionic gelation method, and their thermal stability, chemical structure, mechanical performance, and morphology were characterized. Fatigue-healing performance asphalt mixture with capsules were investigated by indirect tensile fatigue test with intermittent time. Leakage of waste oil core were measure to verify it environmental impact to surroundings. Results showed that all healing agents could restore the aged asphalt, and waste rapeseed oil had superior overall performance with comprehensive fi value of 0.993 in radar chart evaluation. The compression characteristic of the capsules could transform from brittleness to plasticity as the water-to-oil(WO) ratio decreases from 15 to 5. SEM observation implied when the WO ratio varied from 10 to 15, the multi-pore structure of capsules could be appropriately filled. The addition of capsules in the mixture increased the fatigue life extension rate (HDf) of aged mixtures (with intermittent time 0.1 s∼0.8 s) by 10∼30%. Leakage of waste oil from the mixture was inhibited, substantially reducing 38% release of waste oil. This can serve as a means for the sustainable utilization of waste oil, thereby mitigating environmental pollution and negative effects caused by waste oil.

Engineering resveratrol-loaded chitosan nanoparticles for potential use against Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a microorganism directly linked to severe clinical conditions affecting the stomach. The virulence factors and its ability to form biofilms increase resistance to conventional antibiotics, growing the need for new substances and strategies for the treatment of H. pylori infection. The trans-resveratrol (RESV), a bioactive polyphenol from natural sources, has a potential activity against this gastric pathogen. Here, Chitosan nanoparticles (NP) containing RESV (RESV-NP) were developed for H. pylori management. The RESV-NP were prepared using the ionic gelation method and characterized by Dynamic Light Scattering (DLS), Nanoparticle Tracking Analysis (NTA), and, Cryogenic Transmission Electron Microscopy (Cryo – TEM). The encapsulation efficiency (EE) and in vitro release rate of RESV were quantified using high-performance liquid chromatography. RESV-NP performance against H. pylori was evaluated by the quantification of the minimum inhibitory/bactericidal concentrations (MIC/MBC), time to kill, alterations in H. pylori morphology in its planktonic form, effects against H. pylori biofilm and in an in vitro infection model. RESV-NP cytotoxicity was evaluated against AGS and MKN-74 cell lines and by hemolysis assay. Acute toxicity was tested using Galleria mellonella model assays. RESV-NP showed a spherical shape, size of 145.3 ± 24.7 nm, polydispersity index (PDI) of 0.28 ± 0.008, and zeta potential (ZP) of + 16.9 ± 1.81 mV in DLS, while particle concentration was 3.12 x 1011 NP/mL (NTA). RESV-NP EE was 72 %, with full release within the first 5 min. In microbiological assays, RESV-NP presented a MIC/MBC of 3.9 µg/mL, a time-kill of 24 h for complete eradication of H. pylori. At a concentration of 2xMIC (7.8 µg/mL), RESV-NP completely eradicated the H. pylori biofilm, and in an in vitro infection model, RESV-NP (4xMIC – 15.6 µg/mL) showed a significant decrease in bacterial load (1 Log10CFU/mL) when compared to the H. pylori J99 control. In addition, they did not demonstrate a toxic character at MIC concentration for both cell lines. The use of the RESV-NP with mucoadhesion profile is an interesting strategy for oral administration of substances targeting gastric disorders, linked to H. pylori infections.

Unveiling antioxidant capacity of standardized chitosan-tripolyphosphate microcapsules containing polyphenol-rich extract of Portulaca oleraceae

The medicinal plant Portulaca oleraceae has a long history of usage in traditional medicine. Plant extracts have several interesting pharmacological effects but have some drawbacks that can be addressed via capsulation with chitosan. This work set out to do just that tally up the antioxidant effects of a polyphenol-rich P. olerace extract and see how capsulation affected them. The reflux extraction and response surface methodology (RSM) were carried out to optimize the phenolic and flavonoid content of P. oleraceae extract. Additionally, high-resolution mass spectrometry was employed to determine the secondary metabolite present in the extract. The microcapsules of extract-loaded chitosan were prepared using the ionic gelation method and characterized in terms of size, encapsulation efficiency (EE), and morphology of microcapsules. Fourier transform infrared (FTIR) was used to observe the successful production of microcapsules with a principal component analysis (PCA) approach. The antioxidant activity of microcapsules was established using the radical scavenging method. According to RSM, the highest amounts of TPC and TFC were obtained at 72.894% ethanol, 2.031 hours, and 57.384 °C. The compounds were employed from the optimized extract of P. oleraceae including phenolics and flavonoids. The microcapsules were secured with a %EE of 43.56 ± 2.31%. The characteristics of microcapsules were approved for the obtained product's successful synthesis according to the PCA. The microcapsules have antioxidant activity in a concentration-dependent manner (p < 0.0001). The findings of this study underscored the benefits of employing chitosan as a nanocarrier for extract, offering a promising approach to enhance plant-derived therapies.

Hydroxypropyl methylcellulose/sodium alginate/hydroxyapatite nano biomaterial enriched with zinc to promote bone tissue augmentation

Bone is a dynamic connective tissue that provides structural support and locomotion to human physiology. Severe bone degeneration can occur in cases of trauma, infections, genetic disorders, tumors, and hormonal imbalances. This leads to a demand for scaffolds and composites to enhance bone tissue regeneration. The present study aimed to develop a composite material using hydroxypropyl methylcellulose and sodium alginate in combination with hydroxyapatite. The composite was doped with zinc and developed into a nanocomposite using ionic gelation and solvent precipitation methods. The prepared nanocomposite was characterized by scanning electron microscopy, atomic force microscopy, dynamic light scattering, FTIR, and XRD studies. In vivo pharmacological studies were conducted to establish the bone targeting and bone tissue regeneration efficacy of the developed nanocomposite. The nanocomposite was checked for cell toxicity by performing an MTT assay using MG63 cell line and the molecular mechanism of targeting efficiency was assessed by an in silico evaluation method. The results of the study confirmed the polymeric interlinking in the nanocomposite and the successful preparation of a composite material using biodegradable excipients. SEM and AFM studies indicated that the nanocomposite was within the 80-200 nm size range. MTT assay indicated that the developed nanocomposite was not cytotoxic and well tolerated by the MG63 cell line. In vivo, studies in validation with molecular docking evaluation suggested that the nanocomposite was effectively targeted to the bone and enhanced the bone density by blocking Farnesyl Diphosphate Synthetase (FDPS) in the mevalonate pathway which is essential for inhibiting the osteoclastic activity and promoting osteogenesis.

Preparation, Characterization, and Anticancer Activity Assessment of Chitosan/TPP Nanoparticles Loaded with Echis carinatus Venom.

Echis carinatus venom is a toxic substance naturally produced by special glands in this snake species. Alongside various toxic properties, this venom has been used for its therapeutic effects, which are applicable in treating various cancers (liver, breast, etc.). Nanotechnology-based drug delivery systems are suitable for protecting Echis carinatus venom against destruction and unwanted absorption. They can manage its controlled transfer and absorption, significantly reducing side effects. In the present study, chitosan nanoparticles were prepared using the ionotropic gelation method with emulsion cross-linking. The venom's encapsulation efficiency, loading capacity, and release rate were calculated at certain time points. Moreover, the nanoparticles' optimal formulation and cytotoxic effects were determined using the MTT assay. The optimized nanoparticle formulation increases cell death induction in various cancerous cell lines. Moreover, chitosan nanoparticles loaded with Echis carinatus venom had a significant rate of cytotoxicity against cancer cells. It is proposed that this formulation may act as a suitable candidate for more extensive assessments of cancer treatment using nanotechnology-based drug delivery systems.

Synthesis, Characterization and Drug Release Study of Novel Guided Tissue Regeneration Membranes Containing Drug Loaded Chitosan Nanoparticles

Periodontitis is an inflammatory disease which can cause the destruction of the supporting tissues of the tooth leading to tooth loss. The guided tissue regeneration is considered as a gold standard for its treatment but the re-infection of surgical site limits its overall success. Objective: To synthesize novel monolayer guided tissue regeneration (GTR) membrane containing drug loaded chitosan nanoparticles and to evaluate the drug release from the synthesized GTR membranes. Methods: The chitosan nanoparticles containing ciprofloxacin were synthesized by the ionotropic gelation method and these synthesized nanoparticles were added into chitosan GTR membrane fabricated by the freeze gelation method. For comparison GTR membrane was prepared as a control by freeze gelation method in which the drug was added directly. The prepared membranes were characterized by the SEM and FTIR. The drug release was measured from the membrane samples in the phosphate buffer saline (PBS) at 1, 3, 5, 7 and 9 days. Results: The GTR membrane containing the ciprofloxacin loaded chitosan nanoparticles showed fast drug release as compared to the membrane in which the ciprofloxacin was added directly. Conclusions: The inclusion of antibiotic loaded chitosan nanoparticles can increase the drug release from GTR membrane.

Chitosan nanoparticles improve the effectivity of miltefosine against Acanthamoeba.

Acanthamoeba keratitis (AK) is a corneal sight-threatening infection caused by the free-living amoebae of the genus Acanthamoeba. Early and appropriate treatment significantly impacts visual outcomes. Mucoadhesive polymers such as chitosan are a potential strategy to prolong the residence time and bioavailability of the encapsulated drugs in the cornea. Regarding the recent administration of miltefosine (MF) for treating resistant AK, in the present study, we synthesized miltefosine-loaded chitosan nanoparticles (MF-CS-NPs) and evaluated them against Acanthamoeba. Chitosan nanoparticles (CNPs) were prepared using the ionic gelation method with negatively charged tripolyphosphate (TPP). The zeta-potential (ZP) and the particle size of MF-CS-NPs were 21.8±3.2 mV and 46.61±18.16 nm, respectively. The release profile of MF-CS-NPs indicated linearity with sustained drug release. The cytotoxicity of MF-CS-NPs on the Vero cell line was 2.67 and 1.64 times lower than free MF at 24 and 48 hours. This formulation exhibited no hemolytic activity in vitro and ocular irritation in rabbit eyes. The IC50 of MF-CS-NPs showed a significant reduction by 2.06 and 1.69-fold in trophozoites at 24 and 48 hours compared to free MF. Also, the MF-CS-NPs IC50 in the cysts form was slightly decreased by 1.26 and 1.21-fold at 24 and 48 hours compared to free MF. The MF-CS-NPs were more effective against the trophozoites and cysts than free MF. The nano-chitosan formulation was more effective on trophozoites than the cysts form. MF-CS-NPs reduced toxicity and improved the amoebicidal effect of MF. Nano-chitosan could be an ideal carrier that decreases the cytotoxicity of miltefosine. Further analysis in animal settings is needed to evaluate this nano-formulation for clinical ocular drug delivery.

Shear strength recovery of sand with self-healing polymeric capsules

AbstractSelf-healing approaches are increasingly being explored in various fields as a potential method to recover damaged material properties. By self-recovering without external intervention, self-healing techniques emerge as a potential solution to arrest or prevent the development of large strains problems in soils (e.g., landslides) and other ground effects that influence the serviceability of structures (e.g., differential settlement). In this study, a microcapsule-based self-healing sand was developed, and its performance during mixing and compaction, shearing, and recovery of shear strength was demonstrated. The cargo used for sand improvement, a hardening oil, tung oil, was encapsulated in calcium alginate capsules by the ionic gelation method. The surface properties, internal structure, thermal stability and molecular structure of the capsules were evaluated by advanced material characterization techniques. The survivability of capsules during mixing and compaction was assessed by measuring the content of tung oil released into the sand, while their influence on sand shear strength and its recovery was assessed with shear box tests. The results showed that the capsules could rupture due to movement of the sand particles, releasing the tung oil cargo, leading to its hardening and minimizing its strain-softening response and enhancing up to 76% of the sand shear strength (at a normal stress of 10 kPa and capsules content of 4%). This study demonstrates the potential of a capsules-based self-healing system to provide ‘smart’ autonomous soil strength recovery and thus with potential to actively control the large strain behavior of soils.

Preparation of cellulose-paraffin composite foams by an emulsion–gelation method using aqueous inorganic salt solution for thermal energy regulation

Leakage of paraffin phase-change materials during phase transitions limits their application. Cellulose is an environment-friendly material that has the potential to resolve leakage problems. In this study, large-scale, firm, and no leakage cellulose-paraffin composite foams were fabricated via an emulsion–gelation method using a cellulose/LiBr solution. Spherical paraffin particles were embedded into the three-dimensional nanofibrillar network structure of the regenerated cellulose, with no chemical interaction between the paraffin and cellulose. This cellulose-paraffin foam exhibited excellent mechanical properties, with a maximum elastic modulus value of 7.08 MPa. No leakage was observed at 80 °C even when the paraffin content was 80 %. During phase change, the maximum latent heat was 173.2 J g−1. The thermal conductivity was relatively low (46.5–77.2 mW m−1); this represented 23–38 % of the thermal conductivity of pure paraffin. Therefore, foams are promising materials for efficient and reliable thermal energy storage applications.

Levofloxacin loaded chitosan and poly-lactic-co-glycolic acid nano-particles against resistant bacteria: Synthesis, characterization and antibacterial activity

BackgroundWith the global increase in antibacterial resistance, the challenge faced by developing countries is to utilize the available antibiotics, alone or in combination, against resistant bacterial strains. We aimed to encapsulate the levofloxacin (LVX) into polymeric nanoparticles using biodegradable polymers i.e. Chitosan and PLGA, estimating their physicochemical characteristics followed by functional assessment as nanocarriers of levofloxacin against the different resistant strains of bacteria isolated from biological samples collected from tertiary care hospital in Lahore, Pakistan. MethodsLVX-NPs were synthesized using ion gelation and double emulsion solvent-evaporation method employing chitosan (CS) and poly-lactic-co-glycolic acid (PLGA), characterized via FTIR, XRD, SEM, and invitro drug release studies, while antibacterial activity was assessed using Kirby-Bauer disc-diffusion method. ResultsData revealed that the levofloxacin-loaded chitosan nanoparticles showed entrapment efficiency of 57.14% ± 0.03 (CS-I), 77.30% ± 0.08(CS-II) and 87.47% ± 0.08 (CS-III). The drug content, particle size, and polydispersity index of CS-I were 52.22% ± 0.2, 559 nm ± 31 nm, and 0.030, respectively, whereas it was 66.86% ± 0.17, 595 nm ± 52.3 nm and 0.057, respectively for CS-II and 82.65% ± 0.36, 758 nm ± 24 nm and 0.1, respectively for CS-III. The PLGA-levofloxacin nanoparticles showed an entrapment efficiency of 42.80% ± 0.4 (PLGA I) and 23.80% ± 0.4 (PLGA II). The drug content, particle size and polydispersity index of PLGA-I were 86% ± 0.21, 92 nm ± 10 nm, and 0.058, respectively, whereas it was 52.41% ± 0.45, 313 nm ± 32 nm and 0.076, respectively for PLGA-II. The XRD patterns of both polymeric nanoparticles showed an amorphous nature. SEM analysis reflects the circular-shaped agglomerated nanoparticles with PLGA polymer and dense spherical nanoparticles with chitosan polymer. The in-vitro release profile of PLGA-I nanoparticles showed a sustained release of 82% in 120 h and it was 58.40% for CS-III. Both types of polymeric nanoparticles were found to be stable for up to 6 months without losing any major drug content. Among the selected formulations, CS-III and PLGA-I, CS-III had better antibacterial potency against gram+ve and gram-ve bacteria, except for K. pneumonia, yet, PLGA-I demonstrated efficacy against K. pneumonia as per CSLI guidelines. All formulations did not exhibit any signs of hemotoxicity, nonetheless, the CS-NPs tend to bind on the surface of RBCs. ConclusionThese data suggested that available antibiotics can effectively be utilized as nano-antibiotics against resistant bacterial strains, causing severe infections, for improved antibiotic sensitivity without compromising patient safety.

Preparation of celecoxib loaded bioactive glass chitosan composite hydrogels: a simple approach for therapeutic delivery of NSAIDs.

Arthritis causes inflammatory damage to joints and connective tissues. In the treatment of arthritis, precise and controlled drug delivery to the target site is among the frontline research approaches. In the present research work, celecoxib drug and bioactive glass incorporated chitosan hydrogels were fabricated by the freeze gelation method. FTIR, SEM, and TGA/DSC techniques were used to characterize the hydrogels. Different kinetic models were applied to study the drug release kinetics. The celecoxib release was mainly controlled by a Fickian diffusion process followed by the Higuchi model. Maximum 86.2 % drug entrapment was observed in 20 mg drug-loaded hydrogel and its swelling ratio was 115.5% in 28 days. Good hydrophilicity, good drug entrapment efficiency, and moderate drug release patterns of hydrogels can make them suitable for sustained drug release. The cytocompatibility of hydrogels was established by performing an MTT assay on the BHK-21 fibroblast cell line. The promising results have proved that hydrogels can be considered potential material for the slow release of anti-inflammatory drugs at the target site in arthritis.

Olive oil loaded alginate milliparticle with chitosan coating: fabrication and evaluation

PurposeParticles are of the controlled release delivery systems. Also, topically applied olive oil has a protective effect against ultraviolet B (UVB) exposure. Due to its sensitivity to oxidation, various studies have investigated the production of olive oil particles. The purpose of this study was to use chitosan and sodium alginate as the vehicle polymers for olive oil.Design/methodology/approachThe gelation method used to prepare the sodium alginate miliparticles containing olive oil and particles were coated with chitosan. Morphology and size, zeta potential, infrared spectrum of olive oil miliparticles, encapsulation efficiency and oil release profile were investigated. Among 12 primary fabricated formulations, formulations F5 (olive oil loaded alginate miliparticles) and F11 (olive oil loaded alginate miliparticles + chitosan coat) were selected for further evaluations.FindingsThe size of the miliparticles was in the range of 1,100–1,600 µm. Particles had a spherical appearance, and chitosan coat made a smoother surface according to the scanning electron microscopy. The zeta potential of miliparticles were −30 mV for F5 and +2.7 mV for F11. Fourier transform infrared analysis showed that there was no interaction between olive oil and other excipients. Encapsulation efficiency showed the highest value of 85% in 1:4 (olive oil:alginate solution) miliparticles in F11. Release study indicated a maximum release of 68.22% for F5 and 60.68% for F11 in 24 h (p-value < 0.016). Therefore, coating with chitosan had a marked effect on slowing the release of olive oil. These results indicated that olive oil in various amounts can be successfully encapsulated into the sodium-alginate capsules cross-linked with glutaraldehyde.Originality/valueTo the best of the authors’ knowledge, no study has used chitosan and sodium alginate as the vehicle polymers for microencapsulation of olive oil.

Preparation and Investigation of Sustained-Release Nanocapsules Containing Cumin Essential Oil for Their Bacteriostatic Properties.

Cumin essential oil chitosan nanocapsules (CENPs) were prepared through the ionic gelation method by blending chitosan (CS) with cumin essential oil (CEO) in different proportions (1:0.8, 1:1, 1:2, 1:3, 1:4). Subsequently, these nanocapsules were characterized and evaluated for their antibacterial properties to determine the optimal cumin essential oil encapsulation and antibacterial efficacy. The outcomes demonstrated that the highest encapsulation efficiency of CENPs was 52%, achieved with a 1:3 CS/CEO ratio. At this point, the nanoparticles had the smallest particle size (584.67 nm) and a regular spherical distribution in the emulsion. Moreover, the CENPs could release the encapsulated CEOs slowly, leading to efficient inhibition of E. coli and L. monocytogenes over a relatively extended period (24-36 h) compared to the CS and CEO. This research offers a promising approach for the use of nanocapsules in food preservation.

Bee chitosan nanoparticles loaded with apitoxin as a novel approach to eradication of common human bacterial, fungal pathogens and treating cancer.

Antimicrobial resistance is one of the largest medical challenges because of the rising frequency of opportunistic human microbial infections across the globe. This study aimed to extract chitosan from the exoskeletons of dead bees and load it with bee venom (commercially available as Apitoxin [Api]). Then, the ionotropic gelation method would be used to form nanoparticles that could be a novel drug-delivery system that might eradicate eight common human pathogens (i.e., two fungal and six bacteria strains). It might also be used to treat the human colon cancer cell line (Caco2 ATCC ATP-37) and human liver cancer cell line (HepG2ATCC HB-8065) cancer cell lines. The x-ray diffraction (XRD), Fourier transform infrared (FTIR), and dynamic light scattering (DLS) properties, ζ-potentials, and surface appearances of the nanoparticles were evaluated by transmission electron microscopy (TEM). FTIR and XRD validated that the Api was successfully encapsulated in the chitosan nanoparticles (ChB NPs). According to the TEM, the ChB NPs and the ChB NPs loaded with Apitoxin (Api@ChB NPs) had a spherical shape and uniform size distribution, with non-aggregation, for an average size of approximately 182 and 274 ± 3.8 nm, respectively, and their Zeta potential values were 37.8 ± 1.2 mV and - 10.9 mV, respectively. The Api@ChB NPs had the greatest inhibitory effect against all tested strains compared with the ChB NPs and Api alone. The minimum inhibitory concentrations (MICs) of the Api, ChB NPs, and Api@ChB NPs were evaluated against the offer mentioned colony forming units (CFU/mL), and their lowest MIC values were 30, 25, and 12.5 μg mL-1, respectively, against Enterococcus faecalis. Identifiable morphological features of apoptosis were observed by 3 T3 Phototox software after Api@ChB NPs had been used to treat the normal Vero ATCC CCL-81, Caco2 ATCC ATP-37, and HepG2 ATCC HB-8065 cancer cell lines for 24 h. The morphological changes were clear in a concentration-dependent manner, and the ability of the cells was 250 to 500 μg mL-1. These results revealed that Api@ChB NPs may be a promising natural nanotreatment for common human pathogens.

Nanoparticle‐Based Cryogels from Colloidal Aqueous Dispersion: Synthesis, Properties and Applications

AbstractCryogels have morphological features that make them interesting for several applications such as catalysis, sensing or tissue engineering. Their interconnected network and open porous structure, build up by primary particles (such as inorganic nanocrystals or polymers), provide these materials with unique physical properties and high specific surface areas. While the library of cryogels is endless, widely used in the polymer chemistry field, in this review we will summarize the structure and properties, applications and challenges of inorganic nanocrystal‐based cryogels obtained by freezing and freeze‐drying an aqueous nanoparticle colloid. This fast, easy and versatile gelation method will be outlined, along with the corresponding macro‐, micro‐ and nano‐structures and gel morphologies that can be obtained, for example, by changing the freezing temperature or by using one nanoparticle system or nanoparticle mixtures. Their applications towards electrocatalysis, photocatalysis and photoelectrochemical sensing will be highlighted, as well as the challenges and prospects of these materials.

Advances in Injectable Hydrogels Based on Diverse Gelation Methods for Biomedical Imaging.

The injectable hydrogels can deliver the loads directly to the predetermined sites and form reservoirs to increase the enrichment and retention of the loads in the target areas. The preparation and injection of injectable hydrogels involve the sol-gel transformation of hydrogels, which is affected by factors such as temperature, ions, enzymes, light, mechanics (self-healing property), and pH. However, tracing the injection, degradation, and drug release from hydrogels based on different ways of gelation is a major concern. To solve this problem, contrast agents are introduced into injectable hydrogels, enabling the hydrogels to be imaged under techniques such as fluorescence imaging, photoacoustic imaging, magnetic resonance imaging, and radionuclide imaging. This review details methods for causing the gelation of imageable hydrogels; discusses the application of injectable hydrogels containing contrast agents in various imaging techniques, and finally explores the potential and challenges of imageable hydrogels based on different modes of gelation.