Potential Drug Delivery Carrier Research Articles

Degradation and drug release profile of degradable core-corona type particles under acidic condition for cancer treatment

Biodegradable particles are potential drug delivery carriers for cancer treatment because the drugs existed in inner core are released during the degradation of the particles. In this study, graft copolymers were prepared by radical copolymerization of 2-methylene-1,3-dioxepane and poly(ethylene glycol) monomethacrylate. Under acidic condition (pH 1.3), the graft copolymers were degraded through hydrolysis, and after 50-days of hydrolysis, they were converted to hydrophilic oligomers. Degradable core-corona-type particles were prepared by reprecipitation of the graft copolymer solution against water. Under acidic conditions, the diameter of the prepared particles decreased for one day due to the hydrolysis of the particles. The diameter increased after three days due to the swelling of the partially degraded particle cores containing poly(ethylene glycol) chains. Doxorubicin (DOX) release profile was evaluated in a PBS (pH 7.4) and acidic conditions (pH 1.3, 5.4). DOX was not released in PBS, whereas it was released under acidic conditions. The release of DOX increased at lower pH conditions. HeLa cells were cultured in the presence of DOX-loaded particles. Non-DOX-loaded particles showed no cytotoxicity whereas a decrease in cell viability was observed with increasing amounts of DOX-loaded particles. The prepared particles are expected to be useful as degradable drug delivery system carriers for cancer treatment.

Evolving Era of “Sponges”: Nanosponges as a Versatile Nanocarrier for the Effective Skin Delivery of Drugs

Nanosponge, as a carrier for the skin delivery system for drugs, plays a vital role. It not only serves to administer the drug to the targeted layer of skin but also increases the drug retention and deposition on the skin. In this review, we aim to highlight the effects of several processes and formulation variables prompting the characteristics of various nanosponges for the delivery of drugs into/ across the skin. In the present review article, the overall introduction of nanosponges, their preparation, characteristic features, advantages, disadvantages, and factors affecting their preparation, are covered. Furthermore, an elaborative description of nanosponges for skin delivery and its toxicological perspective with some referential examples of nanosponge drugs has also been deliberated here. Factors associated with the formation of nanosponges can directly or indirectly affect its efficacy in the skin delivery of drugs. These nanoforms are efficient in delivering the drugs which possess lower aqueous solubility, therefore, the aqueous solubility of drugs possessing a narrow therapeutic window can easily be enhanced. It also helps in achieving targeted drug delivery, controlled release of drugs, increases bioavailability, reduces drug toxicity, decreases drug degradation, and many more. Nanosponges have been identified as potential drug delivery carriers into as well as across skin. Delivery of biologics such as vaccines, enzymes, peptides, proteins, and antibodies, is also gaining attention in the recent past.

Spanlastics a Novel Nanovesicular Carrier: Its Potential Application and Emerging Trends in Therapeutic Delivery.

Nanotechnology-based drug delivery system has played a very crucial role in overpowering the tasks allied with the conventional dosage form. Spanlastics, an elastic nanovesicle with an ability to carry wide range of drug molecules, make it a potential drug delivery carrier. Spanlastics have extended rising curiosity for diverse sort of route of administration. They can squeeze themselves through the skin pore due to elastic and deformable nature which makes them favorable for transdermal delivery. Spanlastics consist of non-ionic surfactant or blend of surfactants. Many researchers proved that spanlastics have been significantly augment therapeutic efficacy, enhanced drug bioavailability, and reduced drug toxicity. This review summarizes various vesicular systems, composition and structure of spanlastics, advantages of spanlastics over other drug delivery systems, and mechanism of drug penetration through skin. It also gives a brief on different types of drug encapsulated in spanlastics vesicles for the treatment of various diseases.

An injectable supramolecular nanofiber-reinforced chitosan hydrogel with antibacterial and anti-inflammatory properties as potential carriers for drug delivery.

The inherent weak mechanical strength of chitosan physical cross-linking hydrogels (CS hydrogels) limits their applications in biomaterials. Hence, puerarin (PUE) as a self-assembly active small molecule in herbal was introduced in CS hydrogels to fabricate CS/PUE18 composite hydrogels with interpenetrating network structure. The result of rheological measurement showed that storage modulus and loss modulus of CS/PUE18 composite hydrogels were improved by three orders of magnitude, indicating that the introduction of PUE significantly reinforced CS hydrogels. The results of SEM and BET measurement demonstrated that macromolecular chains of CS intertwined with nanofibers of PUE, which caused the network structure of CS/PUE18 composite hydrogels to become denser. XRD patterns and FT-IR spectra verified that the amino groups in CS formed hydrogen bonding with the hydroxyl groups in PUE. Degradation and swelling experiments showed that CS/PUE18 composite hydrogels have pH sensitivity. Moreover, CS/PUE18 composite hydrogels exhibited multi-functionality including injectability, thixotropy, cytocompatibility, antibacterial and anti-inflammatory properties. The release behavior of berberine chloride hydrate (BCH) and PUE from the resultant CS/PUE18 composite hydrogels have pH dependence. These results revealed that injectable CS/PUE18 composite hydrogels with dual antibacterial and anti-inflammatory properties could be potential delivery vehicles for sustained and controlled release.

Dodecaborate-Encapsulated Extracellular Vesicles with Modification of Cell-Penetrating Peptides for Enhancing Macropinocytotic Cellular Uptake and Biological Activity in Boron Neutron Capture Therapy.

Boron neutron capture therapy (BNCT) is a radiation therapy for cancer. In BNCT, the internalization of boron-10 atoms by cancer cells induces cell death through the generation of α particles and recoiling lithium-7 nuclei when irradiated with low-energy thermal neutrons. In this study, we aimed to construct exosomes [extracellular vesicles (EVs)]-based drug delivery technology in BNCT. Because of their pharmaceutical advantages, such as controlled immune responses and effective usage of cell-to-cell communication, EVs are potential next-generation drug delivery carriers. In this study, we successfully developed polyhedral borane anion-encapsulated EVs with modification of hexadeca oligoarginine, which is a cell-penetrating peptide, on the EV membrane to induce the actin-dependent endocytosis pathway, macropinocytosis, which leads to efficient cellular uptake and remarkable cancer cell-killing BNCT activity. The simple and innovative technology of the EV-based delivery system with "cassette" modification of functional peptides will be applicable not only for BNCT but also for a wide variety of therapeutic methodologies.

Development of dietary fiber psyllium based hydrogel for use in drug delivery applications

Keeping in view the therapeutic and gel forming role of the psyllium seed mucilage in pharmaceutical industries, herein this article, its potential has been explored for developing the drug delivery (DD) carrier. The main aim of the study was to modify the psyllium polysaccharides through grafting and crosslinking of 2-methacryloyloxyethyl trimethylammonium chloride onto psyllium to develop the hydrogels for use in DD application. Various thermal, mechanical, physiochemical, biomedical properties of the hydrogel were determined along with characterization with 13C NMR, FTIR, XRD, TGA, DSC and AFM. The release of antibiotic drug cefuroxime occurred in sustained manner and followed Fickian diffusion mechanism and was best fitted in Higuchi kinetic model. The networks showed mesh size in the range between 25.14 to 38.92 nm during the change in crosslinker content in copolymerization reaction. It has been inferred from the results that these hydrogels could be used as a potential carrier for drug delivery.

Isolation and Identification of Adipose Stem Cell Exosomes and the Study of Its Potential as Drug Delivery Carrier In Vitro.

Most small molecule anticancer drugs have high lipophilicity and low water solubility, which is often regarded as a key obstacle to their development and clinical applications. A variety of nano-size drug carriers, like liposomes, has been developed for solubilizing these drugs. Naturally secreted by cells, exosomes have good biocompatibility and are considered as "natural liposomes." Exosomes released by mesenchymal stem cells (MSCs) not only have the properties like the ones generated by other cells but may also possess many therapeutic bioactive factors uniquely secreted by stem cells. In the present study, exosomes secreted by murine adipose stem cells (mASCs) were isolated, identified, and characterized. Its potential as drug delivery carrier and its biological effects on hepatoma cells and normal liver cell lines were explored in vitro. The data indicated that mASC exosomes separated by our improved sequential filtration method have particle size distribution in 30-150nm, positively expresses TSG101, CD63, CD9, GADPH, and negatively expresses calnexin. The exosomes of mASCs obtained by this method could be taken up by cells and inhibit the cell activity of hepatoma cells HepG2, while enhance the normal cell activity of THLE-2. The results suggest that ASC exosomes are ideal potential drug delivery carriers and have the prospect of applications in carcinoma treatments.

Synthesis and Characterization of Acrylamide/Acrylic Acid Co-Polymers and Glutaraldehyde Crosslinked pH-Sensitive Hydrogels.

This project aims to synthesize and characterize the pH-sensitive controlled release of 5-fluorouracil (5-FU) loaded hydrogels (5-FULH) by polymerization of acrylamide (AM) and acrylic acid (AA) in the presence of glutaraldehyde (GA) as a crosslinker with ammonium persulphate as an initiator. The formulation’s code is named according to acrylamide (A1, A2, A3), acrylic acid (B1, B2, B3) and glutaraldehyde (C1, C2, C3). The optimized formulations were exposed to various physicochemical tests, namely swelling, diffusion, porosity, sol gel analysis, and attenuated total reflection-Fourier transform infrared (ATR-FTIR). These 5-FULH were subjected to kinetic models for drug release data. The 5-FU were shown to be soluble in distilled water and phosphate buffer media at pH 7.4, and sparingly soluble in an acidic media at pH 1.2. The ATR-FTIR data confirmed that the 5-FU have no interaction with other ingredients. The lowest dynamic (0.98 ± 0.04% to 1.90 ± 0.03%; 1.65 ± 0.01% to 6.88 ± 0.03%) and equilibrium swelling (1.85 ± 0.01% to 6.68 ± 0.03%; 10.12 ± 0.02% to 27.89 ± 0.03%) of formulations was observed at pH 1.2, whereas the higher dynamic (4.33 ± 0.04% to 10.21 ± 0.01%) and equilibrium swelling (22.25 ± 0.03% to 55.48 ± 0.04%) was recorded at pH 7.4. These findings clearly indicated that the synthesized 5-FULH have potential swelling characteristics in pH 6.8 that will enhance the drug’s release in the same pH medium. The porosity values of formulated 5-FULH range from 34% to 62% with different weight ratios of AM, AA, and GA. The gel fractions data showed variations ranging from 74 ± 0.4% (A1) to 94 ± 0.2% (B3). However, formulation A1 reported the highest 24 ± 0.1% and B3 the lowest 09 ± 0.3% sol fractions rate among the formulations. Around 20% drug release from the 5-FULH was found at 1 h in an acidic media (pH1.2), whereas >65% of drug release (pH7.4) was observed at around 25 h. These findings concluded that GA crosslinked 5-FU loaded AM and AA based hydrogels would be a potential pH-sensitive oral controlled colon drug delivery carrier.

Surface Engineering of Escherichia coli–Derived OMVs as Promising Nano-Carriers to Target EGFR-Overexpressing Breast Cancer Cells

Bacterial outer membrane vesicles (OMVs) have recently drawn a great deal of attention due to their therapeutic efficiency and ability to target specific cells. In the present study, we sought to probe engineered OMVs as novel and promising carriers to target breast cancer cells. Following the fusion of the affiEGFR-GALA structure to the C-terminal of ClyA as an anchor protein, the ClyA-affiEGFR-GALA construct was successfully expressed on the surface of ∆msbB/∆pagP E. coli W3110-derived OMVs. Morphological features of the engineered and wild-type OMVs were identical. The engineered OMVs induced no endotoxicity, cytotoxicity, or immunogenicity, indicating the safety of their application. These OMVs could specifically bind to EGF receptors of MDA-MB-468 cells expressing high levels of EGFR and not to those with low levels of EGFR (HEK293T cells). Interestingly, despite a lower binding affinity of the engineered OMVs relative to the positive control Cetuximab, it was strong enough to identify these cells. Moreover, confocal microscopy revealed no uptake of the modified OMVs by the EGFR-overexpressing cells in the presence of EGFR competitors. These results suggest that OMVs might internalize into the cells with EGF receptors, as no OMVs entered the cells with any EGFR expression or those pretreated with EGF or Cetuximab. Regarding the EGFR-binding affinity of the engineered OMVs and their cellular uptake, they are presented here as a potential carrier for cell-specific drug delivery to treat a wide variety of cancer cells. Interestingly, the engineered OMVs are capable of reaching the cytoplasm while escaping the endosome due to the incorporation of a fusogenic GALA peptide in the construct.

Transferrin conjugated Stealth liposomes for sirolimus active targeting in breast cancer

In the present work Stealth liposomes were conjugated with transferrin (Tf) for sirolimus (SRM) active targeting and the treatment of breast cancer. The developed Tf-Stealth liposomes were assessed for their particle size distribution, zeta potential and drug encapsulation. In vitro evaluation in BT-474 cancer cells demonstrated an antiproliferative effect of the sirolimus loaded Tf-DPPC-Stealth liposomes exhibiting greater cell cytotoxicity compared to Tf-DSPC-Stealth. Sirolimus loaded liposomes were injected intravenously and showed superior anticancer effect for Tf-Stealth nanoparticles with significant tumour growth suppression in comparison to the free drug and non-conjugated Stealth nanoparticles. The results reveal that sirolimus encapsulated Tf-Stealth liposomes are a potential drug delivery carrier for tumour active targeting and the treatment of breast cancer.

Design and evaluation of chitosan-amino acid thermosensitive hydrogel.

Chitosan/glycerophosphate thermosensitive hydrogel crosslinked physically was a potential drug delivery carrier; however, long gelation time limits its application. Here, chitosan-amino acid (AA) thermosensitive hydrogels were prepared from chitosan (CS), αβ-glycerophosphate (GP), and l-lysine (Lys) or l-glutamic acid (Glu). The prepared CS-Lys/GP and CS-Glu/GP hydrogel showed good thermosensitivity and could form gels in a short time. The optimal parameters of CS-Lys/GP hydrogel were that the concentration of CS-Lys was 2.5%, the ratio of CS/Lys was 3.5/1.0, the ratio of CS-Lys/GP was 4.5/1.0. The optimal parameters of CS-Glu/GP hydrogel were that the concentration of CS-Glu was 3.0%, the ratio of CS/Glu was 2.0/1.0, and the ratio of CS-Glu/GP was 4.0/1.5. Chitosan-amino acid (CS-AA) thermosensitive hydrogel had a three-dimensional network structure. The addition of model drug tinidazole (TNZ) had no obvious effect on the structure of hydrogel. The results of infrared spectroscopy showed that there were hydrogen bonds between amino acids and chitosan. In vitro release results showed that CS-Lys/GP and CS-Glu/GP thermosensitive hydrogels had sustained release effects. Thus, the chitosan-amino acid thermosensitive hydrogels hold great potential as a sustained release drug delivery system.

Hydroxyurea anticancer drug adsorption on the pristine and doped C70 fullerene as potential carriers for drug delivery

Recently, C70 and its derivatives, as a representative nanomaterial, have attracted much attention in the field of drug delivery because of their special electronic and geometric structures. Here, we investigated the interactions between hydroxyurea (HU) drug and the pure C70 and heterofullerene MC69 (M = B, Si, Al) by conducting the density functional theory calculations. We calculated the electronic and geometric characteristics in terms of adsorption energy, adsorption configuration, Hirshfeld charge and charge density difference, and frontier molecular orbitals. On the contrary to pure C70, HU molecule was found to be chemisorbed on the SiC69, BC69, and AlC69 molecules with evident charge transfer and moderate adsorption energy. Hence, it is expected that heterofullerene SiC69, BC69, and AlC69 are promising candidates for the delivery of hydroxyurea drug.

Cur-loaded magnetic ZnFe2O4@mZnO-Ox-p-g-C3N4 composites as dual pH- and ultrasound responsive nano-carriers for controlled and targeted cancer chemotherapy

Curcumin (Cur)-loaded zinc ferrite-mesoporous (m) zinc oxide core–shell -oxygen functional groups (carboxyl, carbonyl and hydroxyl) rich mesoporous (p) graphitic (g) carbon nitride (ZnFe2O4@mZnO-Ox-p-g-C3N4) carriers were designed as a potential magnetic drug delivery carrier with pH and ultrasound sensitivity for targeted drug delivery. Application of focused ultrasound can be an effective stimulant for highlighting tumor tissue or activatng delivery of echogenic drugs, which is expected to lower the systemic side effects of chemotherapy. The mixed application of physical/external (ultrasound) and chemical/internal (pH) triggers can allow for targeted release of Cur at chosen sections of tumor tissue. ZnFe2O4@mZnO and ZnFe2O4@mZnO-p-g-C3N4 nano-carriers were characterized using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD), Fourier rransform infra-red (FTIR) spectroscopy, dynamic light scattering (DLS), zeta potential analysis, transmission electron microscopy (TEM), BET (Brunauer–Emmett–Teller), vibrating sample magnetometery (VSM), thermogravimetric analysis (TGA) and in vitro cytotoxicity assays. The ZnFe2O4@mZnOand ZnFe2O4@mZnO-Ox-p-g-C3N4 magnetic nano-carriers showed high loading efficiency of 51.39 and 67.37%, respectively, were stable in water for 24 h. The carriers Nano-carriersshowed pH- and ultrasound-sesnsitive release of Cur. The release at pH = 5.5 for (ZnFe2O4@mZnO 70.28%) (ZnFe2O4@mZnO-Ox-p-g-C3N4 56.05%) was more than that at pH = 7.4 for (ZnFe2O4@mZnO 66.26%) (ZnFe2O4@mZnO-Ox-p-g-C3N4 45.40%) after 72 h.

Preparation of Monodispersed Nanoporous Eu(III)/Titania Loaded with Ibuprofen: Optimum Loading, Luminescence, and Sustained Release.

Functional nanomaterials are one of the potential carriers for drug delivery, whereas there are many prerequisites for this purpose. The carrier should be monodispersed, be fluorescent, and have a proper nanostructure to keep/release drug molecules to achieve controlled release, although preparing a nanomaterial which fulfills all the demands is still very challenging. In this paper, we show the preparation of monodispersed nanoporous amorphous titania submicron particles with fluorescent property. They adsorb a model drug molecule-ibuprofen-with their surface coverage up to 100%. Such a perfect loading does not decrease the fluorescent intensity because of any quenching effects but even maximize it. We also demonstrate the release behavior of IBU into simulated body fluid. Interestingly, the present carrier releases most of IBU in 6 h, whereas that modified with the polyethylene glycol moiety takes 48 h to finish releasing IBU, indicating its potential for controlled release applications.

Fabrication of radiation cross-linked diclofenac sodium loaded carboxymethyl sago pulp/chitosan hydrogel for enteric and sustained drug delivery

Carboxymethyl sago pulp (CMSP) with a degree of substitution 0.8 was synthesised from sago waste and cross-linked with chitosan to form a hydrogel by electron beam (EB) irradiation. Diclofenac sodium was loaded into 40% CMSP/3% chitosan solution mixture and irradiated at 25 kGy. The hydrogel exhibited pH and temperature-sensitive swelling behaviour. Fourier-transform infrared spectroscopy, field emission scanning electron microscope, X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis were performed to characterise its properties. Drug entrapment efficiency of diclofenac sodium-loaded hydrogel was 65.4 ± 0.2%. The release of diclofenac sodium from CMSP/chitosan hydrogel disc was low in an acidic environment (pH 1.2) and there was slow and sustained release in colonic pH (pH 6.8) over 32 h in a first-order manner. Based on the results of the disk diffusion test, the hydrogel exhibited antimicrobial activity against the tested microorganisms. Among tested formulations, 40% CMSP/3% chitosan hydrogel was shown to be the potential drug carrier for sustained drug delivery.

Real-Time Luminescence Assay for Cytoplasmic Cargo Delivery of Extracellular Vesicles.

Extracellular vesicles (EVs) have been considered to deliver biological cargos between cells and mediate intercellular communication and potential drug delivery carriers. However, the mechanisms that underlie the biological process of EV uptake and cytoplasmic cargo release in recipient cells are largely unknown. Quantitative and real-time assays for the assessment of cargo delivery efficiency inside recipient cells have not been feasible. In this study, we developed an EV cargo delivery (EVCD) assay using a split luciferase called a NanoBiT system. Recipient cells expressing LgBiT, a large subunit of luciferase, emit luminescence when EV cargo proteins fused with a small luminescence tag (HiBiT tag) that can complement LgBiT are delivered to the cytoplasm of recipient cells. Using the EVCD assay, the cargo delivery efficiency of EVs could be quantitatively measured in real time. This assay was highly sensitive in detecting a single event of cargo delivery per cell. We found that modification of EVs with a virus-derived fusogenic protein significantly enhanced the cytoplasmic cargo delivery; however, in the absence of a fusogenic protein, the cargo delivery efficiency of EVs was below the threshold of the assay. The EVCD assay could assess the effect of entry inhibitors on EV cargo delivery. Furthermore, using a luminescence microscope, the cytoplasmic cargo delivery of EVs was directly visualized in living cells. This assay could reveal the biological mechanism of the cargo delivery processes of EVs.

Highly cross-linked arabinoxylans microspheres as a microbiota-activated carrier for colon-specific insulin delivery

In vivo evaluation of arabinoxylans (AX) microspheres showed to protect insulin from degradation in the upper gastrointestinal tract and carrier insulin to colon. Insulin-loaded AX microspheres (50 UI/kg) decreased blood glucose level by 39% in diabetic rats with a maximum effect at 18 h post-administration, indicating that insulin remains bioactive. The continuous administration (4 days) of insulin-loaded AX microspheres improved the polyuria and increased the production of short-chain fatty acids, as well as Bifidobacterium and Bacteroides in diabetic rats compared to untreated diabetic rats. AX microspheres are a potential microbiota-activated carrier for colon-specific drug delivery and could be useful as a complementary treatment for diabetes.

Preparation and Evaluation of Azelaic Acid Topical Microemulsion Formulation: In Vitro and In Vivo Study.

The aim of this study was to design oil in water (O/W) microemulsion formulations for the topical administration of azelaic acid. The permeability of azelaic acid through rat skin and the anti-inflammatory activities of the formulations were conducted to examine the efficacy of the designed formulations. Skin irritation and stability tests were also performed. The permeability of azelaic acid was significantly increased by using O/W microemulsions as carriers. The edema index of ear swelling percentage was significantly recovered by the 5% drug-loaded formulation and a 20% commercial product, demonstrating that the experimental formulation possessed comparable effect with the commercial product on the improvement of inflammation. The experimental formulation did not cause significant skin irritation compared to the negative control group. Moreover, the drug-loaded formulation also showed thermodynamic stability and chemical stability after storage for 30 days. In conclusion, the O/W microemulsion was a potential drug delivery carrier for azelaic acid topical application.

Fluconazole-loaded solid lipid nanoparticles (SLNs) as a potential carrier for buccal drug delivery of oral candidiasis treatment using the Box-Behnken design

The purpose of the present examination was to prepare fluconazole (FZ)-loaded solid lipid nanoparticles (FZ-loaded SLNs) for a buccal drug delivery system using the Box-Behnken design. The FZ-loaded SLNs were prepared using hot homogenization via an ultrasonic probe. The solid lipid, stabilizer, and active ingredient were glyceryl monostearate (GMS) (X1), Tween 80® (X2), and FZ (X3), respectively. The particle size of the FZ-loaded SLNs was in the nano-range of 32.86–269.3 nm. The polydispersity index (PDI) showed a relatively narrow size distribution and was in the range of 0.254–0.495. The zeta potential of all formulations was negatively charged and ranged from −19.8 to −36.9 mV. The entrapment efficiency (%EE) was 56.69–85.49%. Transmission electron microscopy confirmed that the FZ-loaded SLNs were in the nano-range and were spherical. The absence of FZ's melting peak in differential scanning calorimetry thermograms of the FZ-loaded SLNs indicated that the drug had been wholly incorporated into the lipid matrix and had changed from crystalline to amorphous form. The absence of FZ's characteristic peaks in the FZ-loaded SLNs in the Fourier transform infrared spectra confirmed the complete incorporation of FZ in the SLN lipid matrix. The maximum of the determination coefficient (R2) of the Higuchi model was much higher than that of the other models, suggesting that the FZ's kinetic release profile was diffusion-controlled. Permeation studies using porcine buccal mucosa were performed, and at 12 h, the drug could be detected in the buccal tissue, including that in the receptor chamber. The in vitro antifungal activity of the selected FZ-loaded SLNs was studied against Candida albicans, and all selected FZ-loaded SLNs showed inhibition zones, indicating that the FZ from the FZ-loaded SLNs had an antifungal effect. Therefore, FZ-loaded SLNs is a promising drug delivery carrier for local and systemic treatment of candidiasis through the buccal mucosa.

TEMPO-Oxidized Cellulose Beads as Potential pH-Responsive Carriers for Site-Specific Drug Delivery in the Gastrointestinal Tract.

The development of controlled drug delivery systems based on bio-renewable materials is an emerging strategy. In this work, a controlled drug delivery system based on mesoporous oxidized cellulose beads (OCBs) was successfully developed by a facile and green method. The introduction of the carboxyl groups mediated by the TEMPO(2,2,6,6-tetramethylpiperidine-1-oxyradical)/NaClO/NaClO2 system presents the pH-responsive ability to cellulose beads, which can retain the drug in beads at pH = 1.2 and release at pH = 7.0. The release rate can be controlled by simply adjusting the degree of oxidation to achieve drug release at different locations and periods. A higher degree of oxidation corresponds to a faster release rate, which is attributed to a higher degree of re-swelling and higher hydrophilicity of OCBs. The zero-order release kinetics of the model drugs from the OCBs suggested a constant drug release rate, which is conducive to maintaining blood drug concentration, reducing side effects and administration frequency. At the same time, the effects of different model drugs and different drug-loading solvents on the release behavior and the physical state of the drugs loaded in the beads were studied. In summary, the pH-responsive oxidized cellulose beads with good biocompatibility, low cost, and adjustable release rate have shown great potential in the field of controlled drug release.