Zeolite in tissue engineering: Opportunities and challenges

Zeolite-Loaded Hydrogels as Wound pH-Modulating Dressings for Diabetic Wound Healing

Wound pH has emerged as a promising therapeutic target in diabetic foot ulcers (DFU). Here, we aimed to develop a microparticle-loaded hydrogel for pH modulation in wound fluid. In a screen of polymeric and inorganic microparticles, zeolites were identified as pH-modulating microparticles. Zeolites were encapsulated in a calcium cross-linked alginate hydrogel, a biocompatible matrix clinically used as a wound dressing. This hydrogel potently neutralized hydroxide ions in serum-containing simulated wound fluid. These findings encourage a further development of this pH-modulating device as a molecular therapeutic system for DFUs.

Neuroprotective effects of punicalagin and/or micronized zeolite clinoptilolite on manganese-induced Parkinson's disease in a rat model: Involvement of multiple pathways

BACKGROUND

Manganism, a central nervous system dysfunction correlated with neurological deficits such as Parkinsonism, is caused by the substantial collection of manganese chloride (MnCl2) in the brain.

OBJECTIVES

To explore the neuroprotective effects of natural compounds, namely, micronized zeolite clinoptilolite (ZC) and punicalagin (PUN), either individually or in combination, against MnCl2-induced Parkinson's disease (PD).

METHODS

Fifty male albino rats were divided into 5 groups (Gps). Gp I was used as the control group, and the remaining animals received MnCl2 (Gp II-Gp V). Rats in Gps III and IV were treated with ZC and PUN, respectively. Gp V received both ZC and PUN as previously reported for the solo-treated plants.

RESULTS

ZC and/or PUN reversed the depletion of monoamines in the brain and decreased acetyl choline esterase activity, which primarily adjusted the animals' behavior and motor coordination. ZC and PUN restored the balance between glutamate/γ-amino butyric acid content and markedly improved the brain levels of brain-derived neurotrophic factor and nuclear factor erythroid 2-related factor 2/heme oxygenase-1 and decreased glycogen synthase kinase-3 beta activity. ZC and PUN also inhibited inflammatory and oxidative markers, including nuclear factor kappa-light-chain-enhancer of activated B cells, Toll-like receptor 4, nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 and caspase-1. Bcl-2-associated X-protein and B-cell leukemia/lymphoma 2 protein (Bcl-2) can significantly modify caspase-3 expression. ZC and/or PUN ameliorated PD in rats by decreasing the levels of endoplasmic reticulum (ER) stress markers (p-protein kinase-like ER kinase (PERK), glucose-regulated protein 78, and C/EBP homologous protein (CHOP)) and enhancing the levels of an autophagy marker (Beclin-1).

DISCUSSION AND CONCLUSION

ZC and/or PUN mitigated the progression of PD through their potential neurotrophic, neurogenic, anti-inflammatory, antioxidant, and anti-apoptotic activities and by controlling ER stress through modulation of the PERK/CHOP/Bcl-2 pathway.

Hemostatic Dressing Immobilized with ε-poly-L-lysine and Alginate Coated Mesoporous Bioactive Glass Prevents Blood Permeation by Pseudo-Dewetting Behavior

The integration of hemostats with cotton fabrics is recognized as an effective approach to improve the hemostatic performance of dressings. However, concerns regarding the uncontrollable absorption of blood by hydrophilic dressings and the risk of distal thrombosis from shed hemostatic agents are increasingly scrutinized. To address these issues, this work develops an advanced dressing (AQG) with immobilized nano-scale mesoporous bioactive glass (MBG) to safely and durably augment hemostasis. The doubly immobilized MBGs, pre-coated with ε-poly-L-lysine and alginate, demonstrate less than 1% detachment after ultrasonic washing. Notably, this MBG layer significantly promotes the adhesion, aggregation, and activation of red blood cells and platelets, adhered five times more red blood cells and 29 times more platelets than raw dressing, respectively. Specially, with the rapid formation of protein corona and amplification of thrombin, dense fibrin network is built on MBG layer and then blocked blood permeation transversely and longitudinally, showing an autophobic pseudo-dewetting behavior and allowing AQG to concentrate blood in situ and culminate in faster hemostasis with lower blood loss. Furthermore, the potent antibacterial properties of AQG extend its potential for broader application in daily care and clinical setting.

Zeolite Properties, Methods of Synthesis, and Selected Applications

Zeolites, a group of minerals with unique properties, have been known for more than 250 years. However, it was the development of methods for hydrothermal synthesis of zeolites and their large-scale industrial applications (oil processing, agriculture, production of detergents and building materials, water treatment processes, etc.) that made them one of the most important materials of the 20th century, with great practical and research significance. The orderly, homogeneous crystalline and porous structure of zeolites, their susceptibility to various modifications, and their useful physicochemical properties contribute to the continuous expansion of their practical applications in both large-volume processes (ion exchange, adsorption, separation of mixture components, catalysis) and specialized ones (sensors). The following review of the knowledge available in the literature on zeolites aims to present the most important information on the properties, synthesis methods, and selected applications of this group of aluminosilicates. Special attention is given to the use of zeolites in agriculture and environmental protection.

Silanol-Engineered Nonclassical Growth of Zeolite Nanosheets from Oriented Attachment of Amorphous Protozeolite Nanoparticles

Zeolite nonclassical growth via particle attachment has been proposed for two decades, yet the attachment mechanism and kinetic regulation remain elusive. Here, nonclassical growth of an MFI-type zeolite has been achieved by using amorphous protozeolite (PZ) nanoparticles containing encapsulated TPA+ templates and abundant silanols (Si-OH) as sole precursors under hydrothermal conditions. The silanol characteristics of the precursor were studied by two-dimensional (2D) solid-state nuclear magnetic resonance (NMR) correlation spectroscopy, which were proven to play critical roles in determining precursor attachment behavior and crystal growth orientation. Under mechanical ball-milling or tablet-pressing process, pressure drove the fusion of spherical PZ into platelet-like integrated PZ (IPZ) coupled with transformations of external silanols from evenly distributed to curvature-dependent distributed and internal silanols from isolated to spatially proximate. Compared to isolated silanols, the spatially proximate silanols possessed a stronger correlation with TPA+, benefiting the formation of Si-O-Si bonds via silanol condensation. Subsequently, driven by minimization of surface energy, particle attachment of the platelet-like IPZ precursor preferentially occurred at high-curvature surfaces with high-density silanols, leading to anisotropic rates of nonclassical growth and thus the formation of high-aspect-ratio MFI-type zeolite nanosheets. Advanced electron microscopy provided direct evidence of attachment of amorphous IPZ precursors to crystalline intermediate surfaces along the c-axis direction with the formation of amorphous-crystalline interfaces, followed by interface elimination and structural evolution to a single-crystalline phase. Our findings not only unravel the zeolite nonclassical growth mechanism but also reveal the critical role of silanol chemistry in kinetic regulation, which is of great importance for pursuing a tailored zeolite synthesis.

Evaluation of bioactivity and biodegradability of a biomimetic soft tissue scaffold for clinical use: An in vitro study

Background

Autogenous soft-tissue graft is the gold-standard approach to augment oral soft tissues. However, tissue engineering is increasingly surveyed to overcome its substantial drawbacks, including the secondary site of operation, patient's pain and discomfort, limited tissue of donor site, and so on. Chitosan and gelatin have been utilized in this field over the years due to their great biological virtues. Zeolite, another remarkable candidate for tissue engineering, possesses outstanding biological and mechanical properties, thanks to its nanostructure. Therefore, this study aimed to investigate the biodegradability and DNA content of seeded human gingival fibroblasts on a New Chitosan-Gelatin-Zeolite Scaffold for the perspective of oral and mucosal soft tissue augmentation.

Materials and Methods

DNA contents of the human gingival fibroblast cell line (HGF.1) seeded on the chitosan-gelatin (CG) and CGZ scaffolds were evaluated by propidium iodide staining on days 1, 5, and 8. Scaffolds' biodegradations were investigated on days 1, 7, 14, 28, 42, and 60.

Results

Although both scaffolds provided appropriate substrates for HGF.1 growth, significantly higher DNA contents were recorded for the CGZ scaffold. Among experimental groups, the highest mean value was recorded in the CGZ on day 8. CGZ showed a significantly lower biodegradation percentage at all time points.

Conclusions

The incorporation of zeolite into the CG scaffold at a ratio of 1:10 improved the cell proliferation and stability of the composite scaffold. CGZ scaffold may offer a promising alternative to soft-tissue grafts due to its suitable biological features.

High-Efficiency Antibacterial Hemostatic AgNP@Zeolite/Chitin/Bamboo Composite Sponge for Wound Healing without Heat Injury

Chitin is a popular hemostatic material, but there are still many deficiencies in its ability to effectively stop bleeding, prevent infection, and fit wounds. Herein, AgNP@zeolite/chitin/bamboo (AgZ-CB) composite sponges with shape recovery are prepared to minimize blood loss, kill bacteria, and promote wound healing. Notably, the bamboo powder is used for the first time to remarkably enhance the softness of the composite sponge (volumetric expansion ratio >5). The fabricated AgZ-CB sponge exhibits an excellent killing effect (≈100% bactericidal rate) against both Escherichia coli and Staphylococcus aureus and activates internal and external coagulation pathways to accelerate hemostasis without causing thermal damage (≈5 °C temperature difference). Moreover, the AgZ-CB sponge shows less blood loss (26 mg) and a shorter time to hemostasis (42 s) than the commercial polyvinyl formal sponge (84 mg and 76 s) in the full-thickness liver injury model. The in vivo wound healing and biodegradation experiment indicate that AgZ-CB with excellent biocompatibility can close wounds efficiently. Overall, the AgZ-CB sponge has great potential in combating a series of obstacles in wound healing.

Essential Oils Encapsulated in Zeolite Structures as Delivery Systems (EODS): An Overview

Essential oils (EO) obtained from plants have proven industrial applications in the manufacturing of perfumes and cosmetics, in the production and flavoring of foods and beverages, as therapeutic agents in aromatherapy, and as the active principles or excipients of medicines and pharmaceutics due to their olfactory, physical-chemical, and biological characteristics. On behalf of the new paradigm of a more natural and sustainable lifestyle, EO are rather appealing due to their physical, chemical, and physiological actions in human beings. However, EO are unstable and susceptible to degradation or loss. To tackle this aspect, the encapsulation of EO in microporous structures as zeolites is an attractive solution, since these host materials are cheap and non-toxic to biological environments. This overview provides basic information regarding essential oils, including their recognized benefits and functional properties. Current progress regarding EO encapsulation in zeolite structures is also discussed, highlighting some representative examples of essential oil delivery systems (EODS) based on zeolites for healthcare applications or aromatherapy.

Zeolites: A series of promising biomaterials in bone tissue engineering

As an important worldwide medical issue, bone defect exhibits a variety of physical and psychological consequences on sufferers. Some features of clinical treatments including bone grafting and limb shortening are not satisfactory. Recently, bone tissue engineering has been considered as the most effective approach to dealing with the issue of bone deformities. Meanwhile, a variety of biomaterials have been rationally designed and created for the bone regeneration and tissue repairing. Among all these admirable biomaterials for bone remodeling, zeolite-based materials can serve as efficient scaffold candidates with excellent osteo-inductivity. In addition, the porous nature and high biocompatibility of zeolites endow them with the ability as ideal substrates for cell adhesion and proliferation. More importantly, zeolites are investigated as potential coating materials for implants because they have been proven to increase osteo-conductivity and aid in local elastic modeling. Last but not least, zeolites can also be used to treat bone disorders and act as dietary supplements during the practical applications. Accordingly, numerous benefits of zeolite prompt us to summarize their recent biomedical progress including but not limited to the distinguishing characteristics, broad classifications, as well as promising usages in bone tissue engineering.

The Effectiveness of Pahae Natural Zeolite-Cocoa Shell Activated Charcoal Nanofilter as a Water Adsorber in Bioethanol Purification

Pahae natural zeolite potentially can be used as a filtration material because of its high adsorption capacity. However, it is known that other supportive materials such as activated charcoal are needed to optimize the utilization of natural zeolite as an adsorber. This study aims to investigate the potential use of activated charcoal which was synthesized from cocoa shells waste and natural zeolite in nanosize as the adsorber in order to increase the concentration of bioethanol. The mixing process of nanozeolite and activated charcoal of cocoa shells was carried out through mechanical mixing, while the nanofilter was made using a press-printing technique followed by sintering at several temperature variations. The results showed that the activated zeolite produced in this study has a particle size of 118.4 nm with water absorption capacity of 52.08%. In line with that, the bioethanol concentration was increased up to 78.92% during the adsorption with a 45 min contact time with water vapor. Thus, based on the results, it can be concluded that nanosized zeolite-based adsorbents and activated charcoal produced from cocoa shells can be utilized as adsorbers to significantly increase the concentration of bioethanol generated.

Cost-effective microwave-assisted hydrothermal rapid synthesis of analcime-activated carbon composite from coal gangue used for Pb2+ adsorption

Heavy metal contamination of water has brought about serious harm to the ecological environment and also threatens human health to a certain extent. In this study, a composite structure comprised of analcime-activated carbon (ANA-AC) was synthesized in situ via a microwave-assisted hydrothermal method using coal gangue (CG) for the potential treatment of Pb²⁺ from aqueous solution. The products were systematically characterized using XRD, SEM, BET, FTIR, and XPS. The results showed that activated carbon was successfully integrated with the structure of the analcime and the BET surface area of the ANA-AC (20.82 m²/g) was much greater than that of the CG (9.33 m²/g) and ANA (10.04 m²/g) independently. The relationship between Pb²⁺ adsorption capacity and the initial solution concentration, adsorbent dosages, contact time, pH, and temperature was studied. Under optimal conditions (Pb²⁺  = 100 mg/L, dosage = 0.1 g, contact time = 6 h, pH = 5.4-6, temperature = 298 K), the maximum adsorption capacity of ANA-AC can reach 100%, which was higher than that of CG and ANA. The Langmuir isotherm model was in good agreement with the data obtained for Pb²⁺ adsorption, and the pseudo-second-order kinetic model was more suitable for describing the experimental data, showing that chemical adsorption was the controlling step during the adsorption process. In summary, analcime-activated carbon composite prepared from coal gangue could be used as an appropriate adsorbent for Pb²⁺ adsorption from an aqueous solution.

Molecular Imaging of Steroid-Induced Osteonecrosis of the Femoral Head through iRGD-Targeted Microbubbles

Osteonecrosis of the femoral head (ONFH) is a disease that is commonly seen in the clinic, but its detection rate remains limited, especially at the early stage. We developed an ultrasound molecular imaging (UMI) approach for early diagnosis of ONFH by detecting the expression of integrin αvβ3 during the pathological changes in steroid-induced osteonecrosis of the femoral head (SIONFH) in rat models. The integrin αvβ3-targeted PLGA or lipid microbubbles modified with iRGD peptides were fabricated and characterized. Their adhesion efficiency to mouse brain microvascular endothelial cells in vitro was examined, and the better LIPOiRGD was used for further in vivo molecular imaging of SIONFH rats at 1, 3 and 5 weeks; revealing significantly higher UMI signals could be observed in the 3-week and 5-week SIONFH rats but not in the 1-week SIONFH rats in comparison with the non-targeted microbubbles (32.75 ± 0.95 vs. 0.17 ± 0.09 for 5 weeks, p < 0.05; 5.60 ± 1.31 dB vs. 0.94 ± 0.81 dB for 3 weeks, p < 0.01; 1.13 ± 0.13 dB vs. 0.73 ± 0.31 dB for 1 week, p > 0.05). These results were consistent with magnetic resonance imaging data and confirmed by immunofluorescence staining experiments. In conclusion, our study provides an alternative UMI approach to the early evaluation of ONFH.

Anti-Reflective Zeolite Coating for Implantable Bioelectronic Devices

Since sunlight is one of the most easily available and clean energy supplies, solar cell development and the improvement of its conversion efficiency represent a highly interesting topic. Superficial light reflection is one of the limiting factors of the photovoltaic cells (PV) efficiency. To this end, interfacial layer with anti-reflective properties reduces this phenomenon, improving the energy potentially available for transduction. Nanoporous materials, because of the correlation between the refractive index and the porosity, allow low reflection, improving light transmission through the coating. In this work, anti-reflective coatings (ARCs) deposited on commercial PV cells, which were fabricated using two different Linde Type A (LTA) zeolites (type 3A and 4A), have been investigated. The proposed technique allows an easier deposition of a zeolite-based mixture, avoiding the use of chemicals and elevated temperature calcination processes. Results using radiation in the range 470–610 nm evidenced substantial enhancement of the fill factor, with maximum achieved values of over 40%. At 590 and 610 nm, which are the most interesting bands for implantable devices, FF is improved, with a maximum of 22% and 10%, respectively. ARCs differences are mostly related to the morphology of the zeolite powder used, which resulted in thicker and rougher coatings using zeolite 3A. The proposed approach allows a simple and reliable deposition technique, which can be of interest for implantable medical devices.

Antibacterial Activity and Cell Responses of Vancomycin-Loaded Alginate Coating on ZSM-5 Scaffold for Bone Tissue Engineering Applications

Despite the significant advancement in bone tissue engineering, it is still challenging to find a desired scaffold with suitable mechanical and biological properties, efficient bone formation in the defect area, and antibacterial resistivity. In this study, the zeolite (ZSM-5) scaffold was developed using the space holder method, and a novel vancomycin-loaded alginate coating was developed on it to promote their characteristics. Our results demonstrated the importance of alginate coating on the microstructure, mechanical, and cellular properties of the ZSM-5 scaffold. For instance, a three-fold increase in the compressive strength of coated scaffolds was observed compared to the uncoated ZSM-5. After the incorporation of vancomycin into the alginate coating, the scaffold revealed significant antibacterial activity against Staphylococcus aureus (S. aureus). The inhibition zone increased to 35 mm. Resets also demonstrated 74 ± 2.5% porosity, 4.3 ± 0.07 MPa strength in compressive conditions, acceptable cellular properties (72.3 ± 0.2 (%control) cell viability) after 7 days, good cell attachment, and calcium deposition. Overall, the results revealed that this scaffold could be a great candidate for bone tissue engineering.

Polydopamine Biomaterials for Skin Regeneration

Designing biomaterials capable of biomimicking wound healing and skin regeneration has been receiving increasing attention recently. Some biopolymers behave similarly to the extracellular matrix (ECM), supporting biointerfacial adhesion and intrinsic cellular interactions. Polydopamine (PDA) is a natural bioadhesive and bioactive polymer that endows high chemical versatility, making it an exciting candidate for a wide range of biomedical applications. Moreover, biomaterials based on PDA and its derivatives have near-infrared (NIR) absorption, excellent biocompatibility, intrinsic antioxidative activity, antibacterial activity, and cell affinity. PDA can regulate cell behavior by controlling signal transduction pathways. It governs the focal adhesion behavior of cells at the biomaterials interface. These features make melanin-like PDA a fascinating biomaterial for wound healing and skin regeneration. This paper overviews PDA-based biomaterials' synthesis, properties, and interactions with biological entities. Furthermore, the utilization of PDA nano- and microstructures as a constituent of wound-dressing formulations is highlighted.

Nanoengineering a metal-organic framework for osteosarcoma chemo-immunotherapy by modulating indoleamine-2,3-dioxygenase and myeloid-derived suppressor cells

Background

The high postoperative recurrence rate and refractoriness of relapsed tumors are still a conundrum for the clinical management of osteosarcoma (OS). New therapeutic options are urgently needed. Depriving the nourishment of myeloid-derived suppressor cells is a novel strategy to improve the immunosuppressive tumor microenvironment for enhanced OS therapy.

Methods

We synthesized a hyaluronic acid (HA)-modified metal–organic framework for combinational chemotherapy and immunotherapy of OS. Zeolitic Imidazolate Framework-8 (ZIF-8) was prepared by a one-pot synthetic method, Gemcitabine (Gem) and D-1-Methyltryptophan (D-1-MT) were loaded into the ZIF-8 during the synthesis process to make ZIF-8@Gem/D-1-MT nanoparticles (NPs). The end product (HA/ZIF-8@Gem/D-1-MT NPs) was obtained by HA modification on the surface of ZIF-8@Gem/D-1-MT NPs. The obtained HA/ZIF-8@Gem/D-1-MT NPs have excellent potential as a drug delivery vector for chemotherapy and immunotherapy in vitro and vivo.

Results

The results indicate that HA/ZIF-8@Gem/D-1-MT NPs were readily taken up by OS cells, and that the Gem and D-1-MT were effectively released into the acidic environment. The HA/ZIF-8@Gem/D-1-MT NPs could efficiently decrease OS cell viability (proliferation, apoptosis, cell cycle, migration and invasion). And HA/ZIF-8@Gem/D-1-MT NPs could reactivate antitumor immunity by inhibiting indoleamine 2,3 dioxygenase and myeloid-derived suppressor cells. Furthermore, animal experiments confirmed that HA/ZIF-8@Gem/D-1-MT NPs could induce intratumoral immune responses and inhibit tumor growth. Additionally, HA/ZIF-8@Gem/D-1-MT NPs have a good safety profile.

Conclusions

Our findings demonstrate that the combination of Gem with D-1-MT brings new hope for the improved treatment of OS, while the generation of the nanosystem has increased the application potential and flexibility of this strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02372-8.

The Effects of Incorporating Ag-Zn Zeolite on the Surface Roughness and Hardness of Heat and Cold Cure Acrylic Resins

One of the most widely used materials for the fabrication of prosthetic dental parts is acrylic resin. Its reasonable mechanical and physical properties make it a popular material for a wide range of dental applications. Recently, many attempts have been made to improve the mechanical and biological properties of this material, such as by adding fibres, nanoparticles, and nanotubes. The current study aimed to evaluate the effects of adding an antimicrobial agent, Ag-Zn zeolite, on the surface roughness and hardness of the denture base resins. Ag-Zn zeolite particles were chemically prepared and added at different concentrations (0.50 wt.% and 0.75 wt.%) to the heat cure (HC) and cold cure (CC) acrylic resins. Zeolite particles were characterized and confirmed using X-ray diffraction (XRD) and Energy-Dispersive X-ray Spectroscopy (EDX) attached with a Scanning Electron Microscope (SEM). Sixty disk shape specimens (40 mm diameter and 2 mm thickness) were fabricated from the HC and CC resins with and without the zeolite. All the specimens were divided into two main groups based on the acrylic resins, then each was subdivided into three groups (n = 10) according to the concentration of the Ag-Zn zeolite. A surface roughness and a hardness tester were used to measure the surface finish and hardness of the specimens. The analysed data showed that the surface roughness values significantly decreased when 0.50 wt.% and 0.75 wt.% zeolite were incorporated in the HC resin specimens compared to the control group. However, this reduction was not significant in the case of CC resin, while the surface hardness was significantly improved after incorporating 0.50 wt.% and 0.75 wt.% zeolite for both the CC and HC resins. Incorporating Ag-Zn zeolite with acrylic resin materials could be beneficial for improving their surface finish and resistance to surface damage as defined by the higher hardness.

Cell-Seeded Biomaterial Scaffolds: The Urgent Need for Unanswered Accelerated Angiogenesis

One of the most arduous challenges in tissue engineering is neovascularization, without which there is a lack of nutrients delivered to a target tissue. Angiogenesis should be completed at an optimal density and within an appropriate period of time to prevent cell necrosis. Failure to meet this challenge brings about poor functionality for the tissue in comparison with the native tissue, extensively reducing cell viability. Prior studies devoted to angiogenesis have provided researchers with some biomaterial scaffolds and cell choices for angiogenesis. For example, while most current angiogenesis approaches require a variety of stimulatory factors ranging from biomechanical to biomolecular to cellular, some other promising stimulatory factors have been underdeveloped (such as electrical, topographical, and magnetic). When it comes to choosing biomaterial scaffolds in tissue engineering for angiogenesis, key traits rush to mind including biocompatibility, appropriate physical and mechanical properties (adhesion strength, shear stress, and malleability), as well as identifying the appropriate biomaterial in terms of stability and degradation profile, all of which may leave essential trace materials behind adversely influencing angiogenesis. Nevertheless, the selection of the best biomaterial and cells still remains an area of hot dispute as such previous studies have not sufficiently classified, integrated, or compared approaches. To address the aforementioned need, this review article summarizes a variety of natural and synthetic scaffolds including hydrogels that support angiogenesis. Furthermore, we review a variety of cell sources utilized for cell seeding and influential factors used for angiogenesis with a concentrated focus on biomechanical factors, with unique stimulatory factors. Lastly, we provide a bottom-to-up overview of angiogenic biomaterials and cell selection, highlighting parameters that need to be addressed in future studies.

A Green Composite Based on Gelatin/Agarose/Zeolite as a Potential Scaffold for Tissue Engineering Applications

Designing a novel platform capable of providing a proper tissue regeneration environment is a key factor in tissue engineering. Herein, a green composite based on gelatin/agarose/zeolite with pomegranate peel extract was fabricated as an innovative platform for tissue engineering. Gelatin/agarose was loaded with pomegranate peel extract-loaded zeolite to evaluate its swelling behavior, porosity, release rate, and cell viability performance. The composite characteristics were evaluated using XRD and DSC. The hydrogel performance can be adjusted for the desired aim by zeolite content manipulation, such as controlled release. It was shown that the green nanocomposite exhibited proper cellular activity along with a controlled release rate. Moreover, the hydrogel composite’s swelling ratio was decreased by adding zeolite. This study suggested a fully natural composite as a potential biomaterial for tissue engineering, which opens new ways to design versatile hydrogels for the regeneration of damaged tissues. The hydrogel performance can be adjusted specifically by zeolite content manipulation for controlled release.

Boron Nitride Nanotube as an Antimicrobial Peptide Carrier: A Theoretical Insight

INTRODUCTION

Nanotube-based drug delivery systems have received considerable attention because of their large internal volume to encapsulate the drug and the ability to penetrate tissues, cells, and bacteria. In this regard, understanding the interaction between the drug and the nanotube to evaluate the encapsulation behavior of the drug in the nanotube is of crucial importance.

METHODS

In this work, the encapsulation process of the cationic antimicrobial peptide named cRW3 in the biocompatible boron nitride nanotube (BNNT) was investigated under the Canonical ensemble (NVT) by molecular dynamics (MD) simulation.

RESULTS

The peptide was absorbed into the BNNT by van der Waals (vdW) interaction between cRW3 and the BNNT, in which the vdW interaction decreased during the simulation process and reached the value of -142.7 kcal·mol-1 at 4 ns.

DISCUSSION

The increase in the potential mean force profile of the encapsulated peptide during the pulling process of cRW3 out of the nanotube showed that its insertion into the BNNT occurred spontaneously and that the inserted peptide had the desired stability. The energy barrier at the entrance of the BNNT caused a pause of 0.45 ns when half of the peptide was inside the BNNT during the encapsulation process. Therefore, during this period, the peptide experienced the weakest movement and the smallest conformational changes.

Synthetic Zeolite Supplementation as a Potential Candidate for the Therapy of Diabetic Syndrome

<b>Background and Objective:</b> Natural and Synthetic Zeolite (SZ) is potentially useful for biopharmaceuticals and bio tools due to its unique and outstanding physical and chemical properties. Thus, the present study aimed to evaluate the possible effect of synthetic zeolite in (STZ)-induced diabetic rats. <b>Materials and Methods:</b> About 4 groups of rats were used, (I) normal control, (II) SZ group, (300 mg/kg/day), (III) STZ group, diabetic rats acted as positive control and (IV) STZ+SZ group, included diabetic rats treated with synthetic zeolite (300 mg/kg/day), statistical analysis comparisons between means were carried out using one-way analysis of variance (ANOVA) followed by a post hock (Tukey) multiple comparisons test at p<u>></u>0.05. <b>Results:</b> After six weeks, treatment of diabetic animals with synthetic zeolite markedly exhibited a significant reduction in glucose, lipids, DNA fragmentation, Alanine Aminotransferase (ALAT), Aspartate Aminotransferase (ASAT), urea, creatinine, Malondialdehyde (MDA) and Nitric Oxide (NO) levels concomitant with a significant rise in insulin, Glutathione (GSH), Superoxide Dismutase (SOD) and Catalase (CAT) values close to the corresponding values of healthy ones. <b>Conclusion:</b> In conclusion, synthetic zeolite exhibits multi-health benefits with promising potentials against STZ-induced diabetes, this behaviour may be attributed to its antioxidant and free radical scavenging mechanisms.

Agarose-based biomaterials for advanced drug delivery

Agarose is a prominent marine polysaccharide representing reversible thermogelling behavior, outstanding mechanical properties, high bioactivity, and switchable chemical reactivity for functionalization. As a result, agarose has received particular attention in the fabrication of advanced delivery systems as sophisticated carriers for therapeutic agents. The ever-growing use of agarose-based biomaterials for drug delivery systems resulted in rapid growth in the number of related publications, however still, a long way should be paved to achieve FDA approval for most of the proposed products. This review aims at a classification of agarose-based biomaterials and their derivatives applicable for controlled/targeted drug delivery purposes. Moreover, it attempts to deal with opportunities and challenges associated with the future developments ahead of agarose-based biomaterials in the realm of advanced drug delivery. Undoubtedly, this class of biomaterials needs further advancement, and a lot of critical questions have yet to be answered.

Mesenchymal Stem Cell Spheroids Embedded in an Injectable Thermosensitive Hydrogel: An In Situ Drug Formation Platform for Accelerated Wound Healing

The ability of mesenchymal stem cells (MSCs) to enhance cutaneous wound healing has been well established. Extensive expansion of cells to reach sufficient cell numbers for regenerating tissues has always limited cell-based therapies. An ingenious solution to address this challenge is to develop a strategy to increase the immunomodulatory effects of MSCs without expanding them. In this study, we employed a simple characteristic of cells. It was observed that an optimized three-dimensional (3D) MSC culture in spheroid forms significantly improved their paracrine effects. An electrospray (ES) encapsulation apparatus was used to encapsulate individual or 3D spheroid MSCs into microscale alginate beads (microbeads). Furthermore, alginate microbeads were embedded in an injectable thermosensitive hydrogel matrix, which gels at skin temperature. The hydrogel fills and seals the wounds cavities, maintains high humidity at the wound area, absorbs exudate, and fixes microbeads, protecting them from direct contact with the harsh wound environment. In vitro investigations revealed that secretion of interleukin 10 (IL-0) and transforming growth factor β1 (TGF-β1) gene was gradually enhanced, providing a delivery platform for prolonged release of bioactive molecules. In vivo study on full-thickness wounds showed granulation and re-epithelialization, only after 7 days. Moreover, increased expression of α-smooth muscle actin (α-SMA) in the first 14 days after treatment ensured wound contraction. Besides, a gradual decrease in α-SMA secretion resulted in reduced scar formation. Well-organized collagen fibrils and high expression of the angiogenesis biomarker CD31 confirmed the promoting effect of the hydrogel on the wound-healing process. The proposed wound-dressing system would potentially be used in scalable and effective cell-based wound therapies.