Cu-crosslinked carboxymethylcellulose/naproxen/graphene quantum dot nanocomposite hydrogel beads for naproxen oral delivery

Recent advances in synergistic use of GQD-based hydrogels for bioimaging and drug delivery in cancer treatment

Graphene quantum dot (GQD) integration into hydrogel matrices has become a viable approach for improving drug delivery and bioimaging in cancer treatment in recent years. Due to their distinct physicochemical characteristics, graphene quantum dots (GQDs) have attracted interest as adaptable nanomaterials for use in biomedicine. When incorporated into hydrogel frameworks, these nanomaterials exhibit enhanced stability, biocompatibility, and responsiveness to external stimuli. The synergistic pairing of hydrogels with GQDs has created new opportunities to tackle the problems related to drug delivery and bioimaging in cancer treatment. Bioimaging plays a pivotal role in the early detection and monitoring of cancer. GQD-based hydrogels, with their excellent photoluminescence properties, offer a superior platform for high-resolution imaging. The tunable fluorescence characteristics of GQDs enable real-time visualization of biological processes, facilitating the precise diagnosis and monitoring of cancer progression. Moreover, the drug delivery landscape has been significantly transformed by GQD-based hydrogels. Because hydrogels are porous, therapeutic compounds may be placed into them and released in a controlled environment. The large surface area and distinct interactions of graphene quantum dots (GQDs) with medicinal molecules boost loading capacity and release dynamics, ultimately improving therapeutic efficacy. Moreover, GQD-based hydrogels' stimulus-responsiveness allows for on-demand medication release, which minimizes adverse effects and improves therapeutic outcomes. The ability of GQD-based hydrogels to specifically target certain cancer cells makes them notable. Functionalizing GQDs with targeting ligands minimizes off-target effects and delivers therapeutic payloads to cancer cells selectively. Combined with imaging capabilities, this tailored drug delivery creates a theranostic platform for customized cancer treatment. In this study, the most recent advancements in the synergistic use of GQD-based hydrogels are reviewed, with particular attention to the potential revolution these materials might bring to the area of cancer theranostics.

Carboxymethyl potato starch hydrogels encapsulated cyclodextrin metal-organic frameworks for enantioselective loading of S-naproxen and its programmed release

A natural polysaccharide-based vehicle is facilely prepared for enantioselective loading of S-naproxen (S-NPX) and its programmed release. Cyclodextrin metal-organic frameworks (CD-MOF) are synthesized through the coordination of K+ with γ-cyclodextrin (γ-CD). Compared with R-NPX, the CD-MOF preferably combines with S-NPX, which can be confirmed by the thermodynamic calculations. The S-NPX loaded CD-MOF (CD-MOF-S-NPX) is grafted with disulfide bond (-S-S-) to improve its hydrophobicity, and the loaded S-NPX is further encapsulated in the chiral cavity of γ-CD by carboxymethyl potato starch (CPS) hydrogels. The intermolecular hydrogen bonding of the CPS hydrogels is prone to be destroyed in mildly basic media (∼pH 8.0), resulting in the swelling of the hydrogels; the -S-S- linkage in the vehicle can be cleaved in the presence of glutathione (GSH), leading to the collapse of the CD-MOF. Therefore, the programmed release of S-NPX can be achieved. Also in this work, the release kinetics is investigated, and the results indicate that the release of S-NPX is controlled by the Higuchi model.

Magnetic nanocomposite through coating mannose-functionalized metal-organic framework with biopolymeric pectin hydrogel beads: A potential targeted anticancer oral delivery system

This study designed magnetic nanocomposite hydrogel beads for a potential targeted anticancer oral delivery system. To end this, nanohybrids of Fe3O4/MIL-88(Fe) (FM) were synthesized through in-situ method by the treatment of terephthalic acid (TPA) and (Fe(NO3)3·9H2O) in the presence of Fe3O4 nanoparticles. They were then modified with mannose sugar as an anticancer receptor to achieve a targeted drug delivery system. After loading methotrexate (MTX), they were coated with pH-sensitive pectin hydrogel beads in the presence of a calcium chloride crosslinker for possible transferring the nanohybrids to the intestine through the acidic environment of the digestive system. The results of different analysis techniques showed that the materials were properly synthesized, coated, and loaded. The designed magnetic nanocomposite hydrogel beads showed pH-sensitive swelling and drug release rate, protecting MTX from the acidic environment of the stomach. MTT test revealed a good cytotoxicity toward colon cancer HT29 cell lines. Remarkably, the functionalization of MTX-loaded FM nanohybrids with mannose (MTX-MFM) enhanced their anticancer properties up to about 20 %. The results recommended that the prepared novel magnetic nanocomposite hydrogel beads have a good potential to be used as a targeted anticancer oral delivery system.

Advances in chitosan-based hydrogels for pharmaceutical and biomedical applications: A comprehensive review

The treatment of diseases, such as cancer, is one of the most significant issues correlated with human beings health. Hydrogels (HGs) prepared from biocompatible and biodegradable materials, especially biopolymers, have been effectively employed for the sort of pharmaceutical and biomedical applications, including drug delivery systems, biosensors, and tissue engineering. Chitosan (CS), one of the most abundant bio-polysaccharide derived from chitin, is an efficient biomaterial in the prognosis, diagnosis, and treatment of diseases. CS-based HGs possess some potential advantages, like high values of bioactive encapsulation, efficient drug delivery to a target site, sustained drug release, good biocompatibility and biodegradability, high serum stability, non-immunogenicity, etc., which made them practical and useful for pharmaceutical and biomedical applications. In this review, we summarize recent achievements and advances associated with CS-based HGs for drug delivery, regenerative medicine, disease detection and therapy.

Preparation of pH-responsive magnetic nanocomposite hydrogels based on k-carrageenan/chitosan/silver nanoparticles: Antibacterial carrier for potential targeted anticancer drug delivery

This study reports the development of new pH-responsive drug delivery systems that are important for the treatment of cancer. The Mentha plant extract was obtained and then used for the biosynthesis of magnetic Ag bio nanoparticles (M-Ag bio-NPs). They were added in the formulation of hybrid hydrogel of k-carrageenan (k-Cr) and chitosan (CS) toward the synthesis of magnetic nanocomposite hydrogels. Their chemical structure and morphology were characterized by different analyses. Doxorubicin (DOX) was used as a model anticancer drug to study the targeted drug release behavior of the synthesized nanocomposite hydrogels (loading capacity: about 98 %). In vitro drug release studies showed that the release profile was noticeably controlled in a pH-dependent manner (higher drug release at pH 5). The antibacterial assessment confirmed the high antibacterial activity for the synthesized hydrogel against S. aureus (MIC values 39.06 μg/mL) and E. coli (MIC values > 19.53). In-vitro cytotoxicity results (MTT assay) demonstrated good biocompatibility (higher than 88 %) for the blank nanocomposite hydrogels, while DOX-loaded nanocomposite hydrogels showed high toxicity (about 22 % in the concentration of 20 μg/mL) against HeLa cells. The results showed that the present nanocomposite hydrogels can be suggested for potential application as an antibacterial and anticancer carrier.

Doped Carbon Quantum Dots Reinforced Hydrogels for Sustained Delivery of Molecular Cargo

Hydrogels have emerged as important soft materials with numerous applications in fields including biomedicine, biomimetic smart materials, and electrochemistry. Because of their outstanding photo-physical properties and prolonged colloidal stability, the serendipitous findings of carbon quantum dots (CQDs) have introduced a new topic of investigation for materials scientists. CQDs confined polymeric hydrogel nanocomposites have emerged as novel materials with integrated properties of the individual constituents, resulting in vital uses in the realm of soft nanomaterials. Immobilizing CQDs within hydrogels has been shown to be a smart tactic for preventing the aggregation-caused quenching effect and also for manipulating the characteristics of hydrogels and introducing new properties. The combination of these two very different types of materials results in not only structural diversity but also significant improvements in many property aspects, leading to novel multifunctional materials. This review covers the synthesis of doped CQDs, different fabrication techniques for nanostructured materials made of CQDs and polymers, as well as their applications in sustained drug delivery. Finally, a brief overview of the present market and future perspectives are discussed.

Hydrogels based on gelatin, xanthan gum, and cellulose obtained by reactive extrusion and thermopressing processes

Polysaccharides and proteins are compatible macromolecules that can be used to obtain biopolymeric hydrogels through physical interactions. In this study, an environmentally friendly strategy is being proposed to produce gelatin-xanthan gum- cellulose hydrogels, without the addition of chemical synthetic crosslinkers. Xanthan gum was employed as an alternative crosslinking agent, and cellulose was used as a potential reinforcing agent in the polymeric matrix. Firstly, the biopolymers were mixed by the extrusion process, and glycerol was used as a plasticizer. Then, the polymeric mixture was molded by thermopressing to obtain hydrogels as laminated films. All hydrogels formulations resulted in films with smooth surfaces, without pores or cracks, resulting in amorphous polymeric matrices. The obtained hydrogels had a pH-dependent degree of swelling, the highest swelling values were obtained at pH 4 (5.3-7.9 g/g) after 24 h of immersion. Cellulose acted as a reinforcing agent for hydrogels, increasing thermal stability, tensile strength, and Young's modulus of films when employed at the higher level (7%). The strategy employed in this study to obtain nontoxic hydrogels without synthetic crosslinkers was effective, resulting in materials with promising properties to be used as pharmaceutical forms to deliver active compounds in cosmetic or pharmaceutical products.

Gentamicin-loaded chitosan/folic acid-based carbon quantum dots nanocomposite hydrogel films as potential antimicrobial wound dressing

BACKGROUND

To provide effective healing in the wound, various carbohydrate polymers are commonly utilized that are highly potent platforms as wound dressing films. In this work, novel antibacterial flexible polymeric hydrogel films were designed via crosslinking polymeric chitosan (CS) with folic acid-based carbon quantum dots (CQDs). To end this, folic acid as a bio-precursor is used to synthesize CQDs through the hydrothermal technique. The synthesized CQDs as a crosslinking agent was performed at different concentrations to construct nanocomposite hydrogel films via the casting technique. Also, gentamicin (GM), L-Arginine and glycerol were supplemented in the formulation of nanocomposite since their antibiotic, bioactivity and plasticizing ability, respectively.

RESULTS

The successful construction of films were verified with different methods (FT-IR, UV-Vis, PL, SEM, and AFM analyses). The GM release profile displayed a controlled release manner over 48 h with a low initial burst release in the simulated wound media (PBS, pH 7.4). Antibacterial and in vitro cytotoxicity results showed a significant activity toward different gram-positive and negative bacterial strains (about 2.5 ± 0.1 cm inhibition zones) and a desired cytocompatibility against Human skin fibroblast (HFF-1) cells (over 80% cell viability), respectively.

CONCLUSION

The obtained results recommend CQDs-crosslinked CS (CS/CQD) nanocomposite as a potent antimicrobial wound dressing.

Mucoadhesive carriers for oral drug delivery

Among the various dosage forms, oral medicine has extensive benefits including ease of administration and patients' compliance, over injectable, suppositories, ocular and nasal. Despite of extensive demand and emerging advantages, over 50% of therapeutic molecules are not available in oral form due to their physicochemical properties. More importantly, most of the biologics, proteins, peptide, and large molecular drugs are mostly available in injectable form. Conventional oral drug delivery system has limitation such as degradation and lack of stability within stomach due to presence of highly acidic gastric fluid, hinders their therapeutic efficacy and demand more frequent and higher dosing. Hence, formulation for controlled, sustained, and targeted drug delivery, need to be designed with feasibility to target the specific region of gastrointestinal (GI) tract such as stomach, small intestine, intestine lymphatic, and colon is challenging. Among various oral delivery approaches, mucoadhesive vehicles are promising and has potential for improving oral drug retention and controlled absorption to treat local diseases within the GI tract, as well systemic diseases. This review provides the overview about the challenges and opportunities to design mucoadhesive formulation for oral delivery of therapeutics in a way to target the specific region of the GI tract. Finally, we have concluded with future perspective and potential of mucoadhesive formulations for oral local and systemic delivery.

Covalent Organic Framework (C6N6) as a Drug Delivery Platform for Fluorouracil to Treat Cancerous Cells: A DFT Study

Continuous studies are being carried out to explore new methods and carrier surfaces for target drug delivery. Herein, we report the covalent triazine framework C₆N₆ as a drug delivery carrier for fluorouracil (FU) and nitrosourea (NU) anti-cancer drugs. FU and NU are physiosorbed on C₆N₆ with adsorption energies of -28.14 kcal/mol and -27.54 kcal/mol, respectively. The outcomes of the non-covalent index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses reveal that the FU@C₆N₆ and NU@C₆N₆ complexes were stabilized through van der Waals interactions. Natural bond order (NBO) and electron density difference (EDD) analyses show an appreciable charge transfer from the drug and carrier. The FU@C₆N₆ complex had a higher charge transfer (-0.16 e^-) compared to the NU@C₆N₆ complex (-0.02 e^-). Frontier molecular orbital (FMO) analysis reveals that the adsorption of FU on C₆N₆ caused a more pronounced decrease in the HOMO-LUMO gap (E_H-L) compared to that of NU. The results of the FMO analysis are consistent with the NBO and EDD analyses. The drug release mechanism was studied through dipole moments and pH effects. The highest decrease in adsorption energy was observed for the FU@C₆N₆ complex in an acidic medium, which indicates that FU can easily be off-loaded from the carrier (C₆N₆) to a target site because the cancerous cells have a low pH compared to a normal cell. Thus, it may be concluded that C₆N₆ possesses the therapeutic potential to act as a nanocarrier for FU to treat cancer. Furthermore, the current study will also provide motivation to the scientific community to explore new surfaces for drug delivery applications.

In-vitro evaluation of the 5-fluorouracil loaded GQDs@Bio-MOF capped with starch biopolymer for improved colon-specific delivery

Herein, for the first time, the photoluminescent graphene quantum dots@Bio-metal organic framework (GQDs@Bio-MOF) nanohybrid was prepared. BET analysis obtained the average pore diameter of GQDs@Bio-MOF about 11.97 nm. The existence of nanoscale porosity in GQDs@Bio-MOF displays its suitability for 5-Fu loading owing to the smaller size of 5-Fu. 5-Fu entrapment efficiency and loading capacity were found to be ~42.04 % and ~4.20 %, respectively (5-Fu@GQDs@Bio-MOF). The 5-Fu@GQDs@Bio-MOF was capped with starch biopolymer (St@5-Fu@GQDs@Bio-MOF), fabricated sample displayed 4.67 for pH_PZC. SEM analysis displayed that the St@5-Fu@GQDs@Bio-MOF microspheres have a spherical shape with a diameter of ~2 μm. The in vitro drug release assay displayed better release behavior for St@5-Fu@GQDs@Bio-MOF than 5-Fu@GQDs@Bio-MOF, releasing about 62.3 % of the entrapped 5-Fu within 96 h of incubation. The 5-Fu release showed the best fitting with the Higuchi model with R² 0.9884. The in vitro cytotoxicity screening outcomes displayed that the St@GQDs@Bio-MOF is a promising biocompatible carrier, with cell viability of higher than 84 %. Accumulation of the results revealed that the St@5-Fu@GQDs@Bio-MOF is a new system with advantages of sustained drug release and biocompatibility that are the main criteria for each newly designed anticancer drug carrier.

High efficiency of in-situ cross-linking and acid triggered drug delivery by introducing tobramycin into injectable and biodegradable hydrogels

High efficiency of in-situ cross-linking and acid triggered drug delivery is realized by introducing tobramycin into the hydrogels. Injectable and biodegradable hydrogels are prepared through two steps: First generation of reactive aldehyde groups in the sodium alginate (A-Alg) and then introduction of antibiotic tobramycin as cross-linker. Due to the formation of dynamic Schiff base bonds between the amino groups in tobramycin and aldehyde groups in A-Alg, the gelation of hydrogels can be realized immediately. Thus, tobramycin acts well as the first role cross-linker and the hydrogels containing tobramycin can be injected into the wound during the treatment. In addition, the acid from the decomposition of organic compounds by the bacteria can break the cross-linking points previously formed by tobramycin in the hydrogels. Therefore, tobramycin can be released and act as the second role model drug to kill the bacteria. Because the hydrogels network is broken, the release of tobramycin is more efficient than the traditional drug delivery from hydrogels by diffusion. Based on these unique properties, the present hydrogels containing tobramycin exhibit a good injectable and biodegradable capability. In addition, due to the existence of the reversible acid-labile linkages in the hydrogels, the hydrogels containing tobramycin are also self-healing, which additionally is favorable for the application of wound dressing. More importantly, the antibacterial hydrogels also demonstrate good biocompatibility in vitro and significantly therapeutic effects on an infected mice model in vivo. Based on the above special properties, the hydrogels cross-linked by tobramycin indicate a new approach to prepare hydrogel dressings with low-cost, non-toxicity and good anti-bacterial performance in the treatment of infectious wounds.

Current Understanding of Hydrogel for Drug Release and Tissue Engineering

Due to their good absorption, satisfactory biocompatibility, and high safety, hydrogels have been widely used in the field of biomedicine, including for drug delivery and tissue regeneration. In this review, we introduce the characteristics and crosslinking methods of natural and synthetic hydrogels. Then, we highlight the design and principle of intelligent hydrogels (i.e., responsive hydrogels) used for drug release. Moreover, we introduce the application of the application of hydrogels in drug release and tissue engineering, and the limitations and research directions of hydrogel in drug release and tissue engineering are also considered. We hope that this review can provide a reference for follow-up studies in related fields.

The synthesis of bacterial cellulose-chitosan zwitterionic hydrogels with pH responsiveness for drug release mechanism of the naproxen

The human digestive and absorption system has a specific pH environment, which makes it difficult to for accurate drug-release. Zwitterionic hydrogel, as a kind of drug carrier, is a feasible response strategy. In this work, a facile method was employed to prepare a series zwitterionic hydrogels composed of BC and chitosan. The composite gels could in-situ formed via Schiff's base reaction between partially oxidated bacterial cellulose and chitosan which exhibited relatively well mechanical properties. Besides, the rich amino and carboxyl groups endowed the hydrogels with excellent pH responsive performance. The minimum swelling rate of the hydrogels appeared at pH 3.5-pH 5.0. In lower or higher pH solutions, the swelling rate was greatly increased. The drug (naproxen) loading of the hydrogels was above 110 mg/g. The release amount of naproxen in the simulated gastric juice was less than intestinal fluid with the sustained release time exceeded 24 h. Through kinetic simulation analysis, the drug release behavior is in accordance with zero-order release model. Such kind of composite hydrogel is suggested to be a potential drug carrier for clinical therapy.

Carboxymethyl starch encapsulated 5-FU and DOX co-loaded layered double hydroxide for evaluation of its in vitro performance as a drug delivery agent

Achieving a new oral drug delivery system with controlled drug release behavior is valuable in cancer therapy. Therefore, for the first time, doxorubicin (DOX) and 5-fluorouracil (5-Fu) were simultaneously co-loaded on the as-synthesized layered double hydroxides LDH(MgAl). The resulted system was encapsulated with carboxymethyl starch to improve its efficiency for colon cancer therapy. Several characterization techniques were used to evaluate the successful synthesis of the CMS@LDH(MgAl)@DOX,5-Fu microspheres. The scanning electron microscopy result showed that the size of prepared microspheres is about 72 μm. Additionally, the presence of one broad peak at 2θ ~ 20 of the X-ray diffraction spectrum approved its amorph nature. The drug release study showed a controlled release profile with ~22% of DOX and 29% of 5-Fu. In addition, the cell viability test outcome confirmed the sustained drug release pattern from CMS@LDH(MgAl)@DOX,5-Fu against the colon cancer cell line. The results suggest that the prepared microspheres are capable to operate as an acceptable formulation for oral co-drug delivery.

Recent advances in the hybridization of cellulose and carbon nanomaterials: Interactions, structural design, functional tailoring, and applications

Due to the good biocompatibility and flexibility of cellulose and the excellent optical, electronic, as well as mechanical properties of carbon nanomaterials (CNMs), cellulose/CNM hybrid materials have been widely synthesized and used in energy storage, sensors, adsorption, biomedicine, and many other fields. In this review, we present recent advances (2016-current) in the design, structural design, functional tailoring and various applications of cellulose/CNM hybrid materials. For this aim, first the interactions between cellulose and CNMs for promoting the formation of cellulose/CNM materials are analyzed, and then the hybridization between cellulose with various CNMs for tailoring the structures and functions of hybrid materials is introduced. Further, abundant applications of cellulose/CNM hybrid materials in various fields are presented and discussed. This comprehensive review will be helpful for readers to understand the functional design and facile synthesis of cellulose-based nanocomposites, and to promote the high-performance utilization and sustainability of biomass materials in the future.

Folic acid-modified photoluminescent dialdehyde carboxymethyl cellulose crosslinked bionanogels for pH-controlled and tumor-targeted co-drug delivery

This work aimed to fabricate a new photoluminescent bionanogel with both targeted anticancer drug delivery and bioimaging potentials. Briefly, at first photoluminescent carbon dots (CDs) were synthesized from the low-cost and more available black pepper with traditional medicinal properties. The as-synthesized dialdehyde carboxymethyl cellulose (DCMC) was used as a safe crosslinker for gelatin crosslinking in the presence of CDs (CDs/DCMC-Gel). Eventually, the residual amine functional groups of gelatin were used for the conjugation of CDs/DCMC-Gel with folic acid (FA) ((CDs/DCMC-Gel)-FA bionanogels). All employed physicochemical characterization methods approved the (CDs/DCMC-Gel)-FA bionanogels fabrication route. SEM analysis specified the spherical morphology with a diameter of ~70-90 nm for it. Curcumin (CUR) and doxorubicin (DOX) respectively were loaded with drug entrapment efficiency of about 44.0% and 41.4%. The release rate for both drugs in acidic conditions was higher than in physiological conditions. In vitro antitumor experiments; MTT, DAPI staining, cellular uptake, and cell cycle tests showed the superior anticancer effect of the CUR@DOX@(CDs/DCMC-Gel)-FA in comparison with free CUR@DOX. Moreover, the (CDs/DCMC-Gel)-FA acted as a hopeful bio-imaging tool. Taken together, the designed (CDs/DCMC-Gel)-FA could be proposed as a promising nanosystem for efficient chemotherapy.

Polysaccharides Composite Materials as Carbon Nanoparticles Carrier

Nanotechnology is a dynamically developing field of science, due to the unique physical, chemical and biological properties of nanomaterials. Innovative structures using nanotechnology have found application in diverse fields: in agricultural and food industries, where they improve the quality and safety of food; in medical and biological sciences; cosmetology; and many other areas of our lives. In this article, a particular attention is focused on carbon nanomaterials, especially graphene, as well as carbon nanotubes and carbon quantum dots that have been successfully used in biotechnology, biomedicine and broadly defined environmental applications. Some properties of carbon nanomaterials prevent their direct use. One example is the difficulty in synthesizing graphene-based materials resulting from the tendency of graphene to aggregate. This results in a limitation of their use in certain fields. Therefore, in order to achieve a wider use and better availability of nanoparticles, they are introduced into matrices, most often polysaccharides with a high hydrophilicity. Such composites can compete with synthetic polymers. For this purpose, the carbon-based nanoparticles in polysaccharides matrices were characterized. The paper presents the progress of ground-breaking research in the field of designing innovative carbon-based nanomaterials, and applications of nanotechnology in diverse fields that are currently being developed is of high interest and shows great innovative potential.

Nanostructured Lipid Carriers-Hydrogels System for Drug Delivery: Nanohybrid Technology Perspective

Advanced hybrid component development in nanotechnology provides superior functionality in the application of scientific knowledge for the drug delivery industry. The purpose of this paper is to review important nanohybrid perspectives in drug delivery between nanostructured lipid carriers (NLC) and hydrogel systems. The hybrid system may result in the enhancement of each component's synergistic properties in the mechanical strength of the hydrogel and concomitantly decrease aggregation of the NLC. The significant progress in nanostructured lipid carriers-hydrogels is reviewed here, with an emphasis on their preparation, potential applications, advantages, and underlying issues associated with these exciting materials.

Cross-linker Free Sodium Alginate and Gelatin Hydrogel: Multiscale Biomaterial Design Framework

Surface functionalization and cross-linking have been adopted extensively by researchers to customize hydrogel properties, especially in the last decade. The clinical translation of such biomaterials is in a poor state...

Naproxen release from carbon dot coated magnetite nanohybrid as versatile theranostics for HeLa cancer cells

Nanohybrid magnetite carbon dots (Fe₃O₄@CDs) were successfully synthesized to improve their applicability in multi-response bioimaging. The nanohybrid was prepared via pyrolysis and further loaded with naproxen (NAP) to promote drug delivery features. The characterization of the synthesized Fe₃O₄@CDs demonstrated the existence of Fe₃O₄ crystals by matching with JCPDS 75-0033 and its narrow size distribution at 11.30 nm; further, FTIR spectra confirmed the presence of Fe–O groups, C–O stretching, C–H sp², and C–O bending, along with dual-active fluorescence and magnetic responses. The nanohybrids also exhibit particular properties such as a maximum wavelength of 230.5 nm, maximum emission in the 320–420 nm range, and slight superparamagnetic reduction (Fe₃O₄: 0.93620 emu per g; Fe₃O₄@CDs: 0.64784 emu per g). The cytotoxicity assessment of the nanohybrid revealed an excellent half-maximal inhibitory concentration (IC₅₀) of 17 671.5 ± 1742.6 μg mL⁻¹. Then, the incorporation of NAP decreased the cell viability to below 10%. The kinetic release properties of NAP are also confirmed as pH-dependent, and they follow the Korsmeyer–Peppas kinetics model. These results indicated that the proposed Fe₃O₄@CDs can be used as a new model for theranostic treatment.

Nanohybrid magnetite carbon dots (Fe₃O₄@CDs) were successfully synthesized to improve their applicability in multi-response bioimaging.

Efficient anchoring CuO nanoparticles on Ugi four-component-functionalized graphene quantum dots: Colloidal soluble nanoplatform with great photoluminescent and antibacterial properties

In this work, sustainable functionalization of graphene quantum dots (GQDs) obtained citric acid via a neoteric green, facile, and straightforward approach for effectively anchoring CuO nanoparticles (CuO NPs) and accordingly...

Preparation of pH-sensitive carboxymethyl cellulose/chitosan/alginate hydrogel beads with reticulated shell structure to deliver Bacillus subtilis natto

pH-sensitive hydrogels have been applied in delivering probiotics and drugs. However, pH sensitivity has been found to be contradictory with structural stability in hydrogel preparation. In this work, a novel strategy based on two systems of sodium carboxymethyl cellulose (CMC)/chitosan (CS) and sodium alginate (SA)/calcium chloride was designed to construct a reticulated shell structure stable for 3 h in simulated gastric fluid (pH 1.2) but began to break up at 2 h in simulated intestinal fluid (pH 6.8), exhibiting obvious pH sensitivity. The embedding rate of Bacillus subtilis natto reached to 67.3%, and the sustained release lasted for more than 10 h. It is implicated that the reticulated shell structure has harmoniously balanced the two incompatible properties of pH sensitivity and sustained release of CMC/CS/SA beads.

Application or function of citric acid in drug delivery platforms

Nontoxic materials with natural origin are promising materials in the designing and preparation of the new drug delivery systems (DDSs). Today's, citric acid (CA) has attracted a great deal of attention because of its special features; green nature, biocompatibility, low price, biodegradability, and commercially available property. So, CA has been employed in the preparation of the various platforms to induce a suitable property on their structure. Recently, several research groups investigated the CA-based platforms in different forms like tablets, dendrimers, hyperbranched polymers, (co)polymer, hydrogels, and nanoparticles as efficient DDSs. By considering an increasing amount of published articles in this field, for the first time, in this review, an overview of the published works regarding CA applications in the design of various DDSs is presented with a detailed and insightful discussion.

Carboxymethyl cellulose/tetracycline@UiO-66 nanocomposite hydrogel films as a potential antibacterial wound dressing

Designing an antibacterial agent with a suitable water vapor permeability, good mechanical properties, and controlled antibiotic release is a promising method for stopping bacterial infection in wound tissue. In this respect, this work aims to prepare novel flexible polymeric hydrogel films via integrating UiO-66 into the polymeric carboxymethyl cellulose (CMC) hydrogel for improving the mechanical and antibiotic release performances. First, we performed a green hydrothermal synthetic method to synthesis UiO-66 and followed by encapsulating Tetracycline (TC) through immersion in its aqueous solution. Also, the casting technique was utilized to integrate different concentrations of the TC-encapsulated UiO-66 (TC@UiO-66, 5% to 15%) in the polymeric CMC matrix (CMC/TC@UiO-66) cross-linked by citric acid and plasticized by glycerol. The release performance showed a low initial burst release with a controlled release over 72 h in the artificial sweat and simulated wound exudate (PBS, pH 7.4) media. The in vitro cytotoxicity and antibacterial activity results revealed a good cytocompatibility toward Human skin fibroblast (HFF-1) cells and a significant activity against both E. coli and S. aureus with 1.3 and 1.7 cm inhibition zone, respectively. The obtained results recommend CMC/TC@UiO-66 films as a potential antibacterial wound dressing.

3D-printed antioxidant antibacterial carboxymethyl cellulose/ε-polylysine hydrogel promoted skin wound repair

Developing a wound dressing for the treatment of large and irregular-shaped wounds remains a great challenge. Herein we developed novel printable bionic hydrogels with antibacterial and antioxidant properties which could effectively overcome the challenge by inhibiting inflammation and accelerating wound healing. The CMC/PL (CP) hydrogels were customized with glycidyl methacrylate (GMA) modified carboxymethyl cellulose (CMC) and ε-polylysine (ε-PL) via ultraviolet (UV) light polymerization using a 3D printer. Except for the high compression modulus (238 kPa), stable rheological properties, and effective degradability, these CP hydrogels also had an excellent inhibitory effect (95%) on both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Remarkably, CP hydrogels could remove the excessive reactive oxygen species (ROS) and protect the fibroblasts from damage. Compared with the commercial dressing (Tegaderm ™ film), CP hydrogels showed a better ability to increase the expression of VEGF and CD31, accelerate granulation tissue regeneration, and promote wound healing. This work provides a new strategy to fabricate on-demand multi-functional hydrogels in the field of skin tissue engineering.

Improved efficacy of Panax notoginseng saponin loaded into BSP/alginate microspheres for the treatment of alcoholic gastric ulcers

Previously, we have reported the evaluations of alginate and Bletilla striata polysaccharide (BSP) in formulation of microsphere, which is a muco-adhesive carrier and can achieve a long duration of gastric retention. The combination of Panax notoginseng (Burk.) and B. striata is a traditional Chinese herbal formula that is used to treat gastric ulcers. BSP, an effective ingredient of B. striata, possesses both medicinal and excipient functions. Panax notoginseng saponin (PNS), which can easily dissolve in water, is the main effective ingredient in P. notoginseng (Burk.) for the treatment of gastric ulcers. However, microspheres containing PNS could directly cause drug leakage, ultimately reducing the encapsulation rate. In this study, PNS was fabricated into a hydrophobic dispersion with slow-release characteristics. Subsequently, PNS was packaged into BSP/alginate microspheres to improve the encapsulation rate. The prepared PNS-loaded microspheres were round, the release characteristics aligned with the Weibull equation, and the active ingredients were released by diffusion and erosion. The developed microspheres improved the effects of PNS and synergistically exerted the pharmaceutical effects of BSP on acute gastric ulcers.

Synthesis of graphene quantum dots and their applications in drug delivery

This review focuses on the recent advances in the synthesis of graphene quantum dots (GQDs) and their applications in drug delivery. To give a brief understanding about the preparation of GQDs, recent advances in methods of GQDs synthesis are first presented. Afterwards, various drug delivery-release modes of GQDs-based drug delivery systems such as EPR-pH delivery-release mode, ligand-pH delivery-release mode, EPR-Photothermal delivery-Release mode, and Core/Shell-photothermal/magnetic thermal delivery-release mode are reviewed. Finally, the current challenges and the prospective application of GQDs in drug delivery are discussed.

Facile preparation of pH-sensitive chitosan microspheres for delivery of curcumin; characterization, drug release kinetics and evaluation of anticancer activity

Curcumin (CUR) is a lowly water-soluble natural polyphenol with chemopreventive and chemotherapeutic activities. Hence, to achieve the system with good CUR loading ability, porous MIL-88 (Fe) was prepared in the presence of the presynthesized graphene quantum dots (GQDs) (GQDs@MIL-88 (Fe)). In the following, CUR loaded in the fabricated GQDs@MIL-88 (Fe) nanohybrid. The characterization techniques; Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL), and Brunauer-Emmett-Teller (BET) analysis showed success in the synthesis of GQDs@MIL-88 (Fe). Moreover, the FT-IR analysis displayed the loading of CUR and the formation of CUR@GQDs@MIL-88(Fe). Chitosan (CS) was used as a green coating to enhance the biocompatibility of the prepared system (CS/CUR@GQDs@MIL-88(Fe). The fabricated microspheres showed pH-sensitive swelling behavior and released 38.3% of CUR in pH 5.0 which is better fitted with the First-order kinetic model (R² = 0.9726). In comparison with CUR@GQDs@MIL-88(Fe), the MTT and DAPI assay exhibited less toxic effect for CS/CUR@GQDs@MIL-88(Fe) against MDA-MB 231 cells. Moreover, the safety of the CS/CUR@GQDs@MIL-88(Fe) confirmed after incubation against MCF 10A as a model of the normal cell line. The results conveyed a new concept that the CS/CUR@GQDs@MIL-88(Fe) is a potential candidate for using as a biocompatible carrier with controlled drug delivery ability.