pH-sensitive Drug Carrier Research Articles

Hydrazidomethyl starch as a pH-sensitive coating for magnetic core in tailored magnetic nanoparticles with selective doxorubicin release

The work aimed to use and modify starch as a biodegradable and biocompatible polysaccharide to create a modern pH-sensitive anticancer drug carrier based on a hydrazone bond. The multi-step reaction created a material that can bind to the carbonyl group of anticancer drugs. Additionally, polysaccharide was used to coat magnetic nanoparticles to increase the applicability of the carrier system. At each synthesis stage, the material was characterized in detail by performing FTIR-ATR spectra, thermal analysis, XRD, and SEM photos. In the next step, doxorubicin was loaded with a maximum of 19 % drug loading to the carrier via hydrazone bond. In the last research stage, the carrier-hydrazone bond-drug system was tested in solutions with different pH values, imitating the environments of a cancer cell, a healthy cell, and their subcellular elements regarding drug release from the carrier. The obtained release results indicate a >4-fold increase in the amount of drug released from the carrier in conditions of a slightly lower pH environment (70 %), compared to neutral pH (15 %). This represents a promising potential for using the material as an intelligent drug delivery system (DDS).

Alginate/hyaluronic acid/gelatin ternary blended films as pH-sensitive drug carriers: In vitro ampicillin release and kinetic studies

Researchers continuously focused on the fabrication of innovative drug delivery systems to prevent microbial infections while minimizing systemic side effects. Among these, pH-sensitive antibiotic release systems based on bio-based materials have gained great attention due to their ability to precisely modulate drug kinetics and enhance therapeutic efficacy. Herein, pH-sensitive alginate/hyaluronic acid/gelatin ternary blended films were fabricated for the controlled release of ampicillin. Swelling capacity, hydrolytic degradation profile, pH reversibility and in vitro ampicillin release behavior of produced films were investigated in both simulated gastric (pH 1.2) and intestinal (pH 7.4) environments. The cumulative release amount of ampicillin at pH 1.2 (61.0 ± 1.07 mg drug/g polymer) was greater than that of at pH 7.4 (43.0 ± 1.05 mg drug/g polymer) proved that release behavior of ampicillin for produced films is pH-dependent. Based on the fitted release data, best fit was found as the first-order kinetic model with the highest R2 values of 0.966 and 0.962 for both pH conditions. According to Korsmeyer-Peppas model, drug release mechanism is also controlled by case II-transport. Furthermore, produced films demonstrated excellent cytocompatibility. All results revealed that obtained films could be a promising drug carrier to traditional targeting systems for site-specific, pH-sensitive ampicillin delivery in both gastric and intestine.

A novel pH-sensitive drug carrier system based on 18-crown ether-6/sodium alginate for curcumin/nido-carborane encapsulation: Studies of release properties, cell imaging and bioactivity evaluation

Curcumin's remarkable anti-tumor action has drawn a lot of interest, however its low bioavailability, poor targeting, and poor water solubility restrict its therapeutic potential. Two fluorescent polymers based on curcumin/nido-carborane-crown ether were produced using a two-phase technique in this study: Cur/Carborane-C/SA (encapsulated with sodium alginate) and Cur/Carborane-C (without sodium alginate). Cur/Carborane-C/SA was thought to be the most promising polymer with anti-tumor properties. The drug delivery method based on the polymer created by tris (3-aminoethyl) amine (TAEA) and 18-crown ether-6 in combination with sodium alginate offers a novel approach to curcumin encapsulation technology. Nido-carborane improves the targeting of curcumin and its tumor-cell-inhibiting properties. Good fluorescence qualities were shown by Cur/Carborane-C/SA's fluorescence quantum yield of 0.119 %. According to in vitro drug release data, the polymer performed well for pH response release at 5.0. The TEM and particle size data demonstrated that curcumin produced uniformLy sized, difficult to agglomerate nanoparticles with a particle size of less than 300 nm. The polymer exhibited a substantial affinity and inhibition of HCT-116 and HeLa cells, with an inhibition rate that may reach 78.3 %, according to the findings of the cytotoxicity assay and cell imaging. As a result, it is anticipated that the produced Cur/Carborane-C/SA would provide a new pH-responsive drug carrier system for curcumin intended for use in cancer treatment.

PH-sensitive docetaxel-loaded chitosan/thiolated hyaluronic acid polymeric nanoparticles for colorectal cancer.

Aim: This study aimed to develop and evaluate pH-sensitive docetaxel-loaded thiolated hyaluronic acid (HA-SH) nanoparticles (NPs) for targeted treatment of colon cancer. Materials & methods: HA-SH, synthesized via oxidation and subsequent covalent linkage to cysteamine, served as the precursor for developing HA-SH NPs through polyelectrolyte complexation involving chitosan and thiol-bearing HA. Results & conclusion: HA-SH NPs displayed favorable characteristics, with small particle sizes (184-270nm), positive zeta potential (15.4-18.6mV) and high entrapment efficiency (91.66-95.02%). In vitro, NPs demonstrated potent mucoadhesion and enhanced cytotoxicity compared with free docetaxel. In vivo assessments confirmed safety and biocompatibility, suggesting HA-SH NPs as promising pH-sensitive drug carriers with enhanced antitumor activity for colorectal cancer treatments.

Влияние состава оболочки на эффективность интернализации рН-чувствительных лекарственных носителей на основе мезопористых частиц

Recent advancements in systemic drug delivery emphasize the use of innovative technologies, such as pH-sensitive drug carriers, to achieve precise and efficient targeting within the body. These approaches hold significant promise for controlling drug delivery and guiding drugs to specific targets. This study investigates the fabrication of core-shell particles utilizing mesoporous vaterite particles coated with pH-sensitive alginate and cellulose. The research reveals that the formed coatings influence alterations in particle morphology and zeta potential, resulting in consistent pH-dependent release profiles. Furthermore, the negative potential reduces the uptake efficiency of the resulting particles into Raw264.7 immune cells, demonstrating the potential for prolonged circulation time and increased bioavailability of the encapsulated substances. These findings underscore the potential efficacy of such systems for targeted drug delivery and their potential impact within the context of pH-sensitive drug delivery systems.

Complexation of drug amifampridine with Cu(II), Zn(II) and Cd(II) ions, and its dimerization with the magic of Mn(II) salts. Potential anti-COVID-19 and anticancer activities.

The different behaviors of the drug amifampridine (AMP) against Mn(II), Cu(II), Zn(II) and Cd(II) metal ions, in the presence and absence of tris(2-aminoethyl)amine (tren) was studied. The results showed that AMP successfully coordinates with Cu(II), Zn(II) and Cd(II) metal ions, but interestingly it undergoes an unexpected dimerization through a C-H activation in the presence of different Mn(II) salts. A four-coordinate complex of zinc(II), [Zn(AMP)2Cl2] (1), a binuclear complex of cadmium(II), [Cd2(AMP)2Cl4] (2), three five-coordinate tren-based metal complexes, [Cu(tren)(AMP)](ClO4)2 (8), [Zn(tren)(AMP)]Cl2 (9) and [Cd(tren)(AMP)](ClO4)2 (10), three pyridinium salts, [AmpDimer]X (X = Cl-, NO3-, ClO4-; (3, 4 & 5)), and also two four-coordinate metal complexes with this pyridinium cation, [Zn(AmpDimer)Cl3] (6) and [Cd(AmpDimer)Cl3] (7), were synthesized. All new compounds were characterized by elemental analysis and IR spectroscopy, and by 1H- and 13C-NMR spectroscopy (for 1, 2, 3, 6, 7, 9 & 10) and by X-ray crystal structure determinations (for 1, 3, 4, 5, 7, 8 & 10). Theoretical studies showed that the [M(tren)(AMP)]2+ cations act as pH-sensitive drug carriers of AMP and release it upon protonation. The molecular docking studies on the interaction of AMP and the above complexes/salts with DNA and the proteins of SARS-CoV-2 showed that the synthesized complexes/salts have greater anticancer and anti-covid-19 activities than AMP alone.

Flower-shaped covalent organic framework synthesis and its anticancer drug delivery application

Fabrication of covalent organic frameworks (COFs) at room temperature is necessary due to their easy preparation, practical scale-up, and low cost to overcome the limitations of solvothermal and high-temperature synthesis. Herein, we fabricated flower-shaped COFs (FSCOFs) that were synthesized in various ratios of ortho-xylene and butanol mixture solvents. The FSCOFs exhibited excellent crystallinity with a pore size of approximately 10 nm, which was confirmed by PXRD and BET measurements. To utilize the FSCOFs as a drug carrier, doxorubicin (DOX) was loaded, followed by encapsulation of hyaluronic acid to increase the colloidal stability of FSCOFs in a physiological environment (FSCOFs-DOX-HA). The encapsulation efficiency and the drug loading capacity of FSCOFs-DOX-HA were 21.23 % and 29.82 %, respectively. Moreover, 92 % and 59 % of DOX is released in acidic environments and elevated GSH environments, proving the sensitivity of the FSCOFs as carriers. The excellent drug release mechanism of FSCOFs-HA-DOX is demonstrated by FSCOFs imine nitrogen protonation under acidic environment confirmed by its zeta potential changes under various physiological environments. The designed FSCOFs-DOX-HA was demonstrated to be a pH-sensitive drug carrier to deliver anticancer drugs into cancer cells. The MTT and drug internalization data demonstrated sustained DOX release from FSCOFs-DOX-HA. Finally, the real-time fluorescence demonstrates the effectiveness of the FSCOFs-DOX-HA upon cellular uptake and release of the anticancer drug. Thus, the FSCOFs system reported here opens a new path in COF research for drug carrier systems.

Production and Characterization of Colon Targeted pH Sensitive Macrospheres and Investıgation of Release Kinetics

The gastrointestinal track has different pH values at different sections. Thus, it is not easy to carry a drug to the colon for absorption. pH sensitive polymeric macrosphere drug carriers have important advantages such as being able to be taken orally, targeting the active ingredient to the desired area and dosing the active ingredient at the desired concentration for a long time in the target area. In this contex pH sensitive sodium alginate-gelatin macrospheres were produced by the dispersion phase gelling and cross-linking (complex coacervation) process method then loaded with Sternbergia lutea extract in this study. The macrosphere extract release kinetics were investigated for different pH medias that simulates different sections of the gastrointestinal track. As a result, the produced drug carrier macrospheres released the active ingredient at the colon pH (pH 7.0) while at lower pH values did not show a significant extract release. Therefore, it was reported that the produced macrospheres have potential to be used for colon diseases treatments.

Synthetic Lignin-Derived Therapeutic Nano Reagent as Intestinal pH-Sensitive Drug Carriers Capable of Bypassing the Gastric Acid Environment for Colitis Treatment.

Oral drug delivery is a common route for management of inflammatory bowel disease (IBD) but suffers from low bioavailability and systemic side effects during passage through the alimentary canal. Here, we present a therapeutic nano reagent of a ferulic acid-derived lignin nanoparticle (FALNP). We showed that FALNP with favorable antioxidant activity can regulate IBD. More importantly, the intestinal pH-responsive degradability of FALNP allows it to withstand the harsh gastric acid environment, bypass physiological barriers, and target the intestine for gastrointestinal delivery. In vivo experiments showed that oral administration of FALNP markedly relieved pathological symptoms in a mouse model of acute colitis by reducing oxidative stress and regulating the gut microbiome. By integrating anti-inflammatory medicine, FALNP also can be used as a bioactive carrier to exert a potent synergistic therapeutic effect. In addition to colitis, FALNP can be readily adaptable for use as a carrier platform for therapy of many other intestinal diseases.

Chitosan-Boric Acid Scaffolds for Doxorubicin Delivery in the Osteosarcoma Treatment.

Biologically compatible chitosan-based scaffolds have been considered a promising platform for tissue regeneration, tumor treatment, and targeted drug delivery. Chitosan-based scaffolds can be utilized as pH-sensitive drug carriers with targeted drug delivery resulting in less invasive tumor treatments. Further improvement with bioactive ions, such as borate ions, can result in the dual functionality of chitosan carriers provided by simultaneous antitumor efficacy and tissue regeneration. Here, boric acid-containing crosslinked chitosan scaffolds were prepared as delivery systems of doxorubicin, a chemotherapy drug used in the treatment of osteosarcoma. The encapsulation of boric acid was indicated by FTIR spectroscopy, while the ICP-MS analysis indicated the rapid release of boron in phosphate buffer (pH 6.0) and phosphate-buffered saline solution (pH 7.4). The obtained chitosan-boric acid scaffolds exhibit a highly porous and interconnected structure responsible for high swelling capacity, while enzymatic degradation indicated good scaffolds stability during four weeks of incubation at pH 6.0 and 7.4. Furthermore, the release of doxorubicin investigated in phosphate buffers indicated lower doxorubicin concentrations at pH 7.4 with respect to pH 6.0. Finally, the cytotoxicity of prepared doxorubicin-encapsulated scaffolds was evaluated on human sarcoma cells indicating the scaffolds' potential as cytostatic agents.

Metal-organic framework/carboxymethyl starch/graphene quantum dots ternary hybrid as a pH sensitive anticancer drug carrier for co-delivery of curcumin and doxorubicin

BackgroundThe efficiency of graphene quantum dots (GQDs) and glutamic acid-based metal-organic framework (Bio-MOF(Zn)) compounds have been reported in the drug delivery area. In addition, carboxymethyl starch (CMS) has a good performance in improving biocompatibility and obtaining a controlled anticancer drug release system. Fabrication of Bio-MOF(Zn)@CMS/GQDs can be hopeful in cancer treatment. MethodsIn this work for the first time, a novel pH-sensitive and biocompatible drug carrier was prepared with the combination of CMS, GQDs, and Bio-MOF(Zn) for curcumin (CUR) and doxorubicin (DOX) co-delivery. For this, GQDs were prepared via pyrolysis of citric acid (CA). Then the CMS and GQDs mixture was crosslinked with zinc metal (Zn-CMS/GQDs). Finally, the Bio-MOF(Zn) was simply fabricated in the presence of L-glutamic acid (Glu) as proteinogenic amino acid and Zn-CMS/GQDs as a biocompatible platform (Bio-MOF(Zn)@CMS/GQDs). Significant findingsThe formation of zinc-glutamate Bio-MOF in the presence of Zn-CMS/GQDs was elucidated by the common characterization techniques. Brunauer-Emmett-Teller (BET) analysis obtained the pore diameter of Bio-MOF(Zn)@CMS/GQDs ternary hybrid at about 4.5 nm. The in vitro drug loading test obtained the loading percentage of CUR and DOX at about 54.2% and 43.2%. Moreover, the pH-sensitive drug release behavior was observed. Cellular tests confirmed the biocompatibility of Bio-MOF(Zn)@CMS/GQDs and its capability for cancer cell treatment after drug loading. A Survey of the published research works shows that the studied Bio-MOF(Zn)@CMS/GQDs as a DOX and CUR co-carrier have novelty from both components and application viewpoints. In conclusion, the obtained results can render the Bio-MOF(Zn)@CMS/GQDs ternary hybrid as a newly introduced smart candidate for anticancer drug delivery with great potential in biomedicine.

MXene Quantum Dot/Zeolitic Imidazolate Framework Nanocarriers for Dual Stimulus Triggered Tumor Chemo-Phototherapy.

It is critical to construct stimuli-responsive multifunctional nanoparticles for the drug delivery system for cancer treatment. Zeolitic imidazolate framework-8 (ZIF-8) has a large specific surface area and decomposes quickly under acidic conditions, which presents an excellent potential in pH-sensitive drug carriers. However, the mere chemotherapeutic drug loaded into ZIF-8 is a monotherapy and may restrict the therapeutic efficacy of malignancies. In this work, an effective nanoparticle-based delivery platform is established to simultaneously encapsulate doxorubicin (DOX) and MXene quantum dot (MQD) in ZIF-8 nanoparticles (MQD@ZIF-8/DOX). Under near-infrared (NIR) laser (808 nm) and UV light (365 nm) irradiation, MQD@ZIF-8 demonstrates a high photothermal conversion efficiency and reactive oxygen species (ROS) production, which shows excellent photothermal therapy and photodynamic therapy effects. Furthermore, the release of DOX-loaded into MQD@ZIF-8 nanoparticles is significantly increased under NIR laser irradiation and at pH 5.6, indicating that acidic conditions and NIR laser irradiation can be effectively combined to stimulate the drug release. The cellular experiments show that MQD@ZIF-8/DOX has an obvious killing effect on HeLa cells and achieves the combined anti-tumor effect of chemotherapy and phototherapy.

PRODUCTION OF GANODERMA LUCIDUM EXTRACT LOADED GELATIN-SODIUM ALGINATE MICROSPHERES, INVESTIGATION OF RELEASE KINETICS AT DIFFERENT pH VALUES AND EVALUATION OF KINETIC MODELS

In this study, pH sensitive microsphere polymeric drug carriers were produced by using biodegradable natural gelatin and sodium alginate polymers. Microspheres were loaded with prepared Ganoderma lucidum extract that is a medicinal mushroom and has the potential to be used in several diseases’ treatment. Extract release kinetics of the microspheres were examined by spectrophotometric method by using an UV spectrometer. Buffer solutions with different pH values were used as release medium for examination of drug release kinetics of the produced microspheres. The Ganoderma lucidum release of microspheres was presented in terms of percent cumulative release (CR%) defined as the percentage ratio of the instantaneous amount of Ganoderma lucidum released at a certain time of incubation to the initial amount of Ganoderma lucidum loadings. As a result, it was seen that the release of the extract accelerated as pH of the release medium increased and the fastest extract release was observed in the pH 7. The release kinetic models of the microspheres were examined. The release kinetics of microspheres fitted Higuchi model for pH 1.3, pH 5.0 and pH 6.0 and first-order model for pH 3.0 and pH 7.0.

Facile Fabrication of Cellulose Nanofibrils/Chitosan Beads as the Potential pH-Sensitive Drug Carriers.

It is highly desirable to develop a safe, highly efficient, and biodegradable drug carrier with an enhanced drug transport efficiency. Cellulose nanofibrils (CNF) and chitosan (CS) composite hydrogels are promising candidate carriers with biological compatibility and non-cytotoxicity. Herein, the CNF/CS composite beads were prepared by dissolving cellulose and CS in LiBr molten salt hydrate and regenerating in ethanol. This preparation method is facile and efficient, and the obtained porous CNF/CS beads with the weight ratio of 8:2 exhibited a large specific surface area, uniform micro-nano-sized pores, strong mechanical property, and water absorption-resistance. Moreover, these beads as drug (tetracycline hydrochloride, TH) carriers showed a higher encapsulation efficiency (47.4%) at the TH concentration of 5 mg/mL in 24 h, and a higher drug loading rate (12.0%) than pure CNF and other CNF/CS beads prepared with different ratios. In addition, the TH releasing behavior of CNF/CS (8:2) beads fitted well into the zero-order, first-order, and Higuchi models under an acid condition, indicating that the drug release of these pH-sensitive beads was mainly affected by drug concentration under an acid condition. Therefore, these CNF/CS beads have great potential to be used as drug carriers for medical applications.

Formulation of pH-sensitive aminated chitosan–gelatin crosslinked hydrogel for oral drug delivery

The objective of this study is to develop efficient pH-sensitive hydrogel based on aminated chitosan (AmCs) and gelatin (Gel) biopolymers for oral drug delivery. Herein, AmCs was chemically crosslinked with gelatin (Gel) biopolymer with different ratios, while their structures, thermal profiles and morphological properties were investigated by FTIR, TGA and SEM characterization tools, respectively. Moreover, gel-content, crosslinking density and rheological analysis were also performed. The results clarified that the developed AmCs-Gel crosslinked hydrogel displayed variable pH-sensitive swelling profiles. By increasing AmCs ratio, the swelling ratio was boosted at pH 1.2 and declined at pH 7.4. Besides, by increasing gelatin ratio in the hydrogel matrix, the loading efficiency of Oseltamivir phosphate (as a model of drug) was augmented and reached maximum value of 79.0% by AmCs-Gel (2:3) crosslinked hydrogel. The in vitro drug release profiles were investigated for 6 h in simulated gastric fluid [SGF; pH 1.2] and simulated colon fluid [SCF; pH 7.4]. Variable release profiles were realized depending on variation of AmCs and Gel ratios in the crosslinked hydrogel matrix. Finally, the formulated smart crosslinked AmCs-Gel hydrogels demonstrated acceptable biodegradability with no cellular toxicity, suggesting their applicability as pH-sensitive oral drug carriers.

Fe3O4@PEG-coated dendrimer modified graphene oxide nanocomposite as a pH-sensitive drug carrier for targeted delivery of doxorubicin

Since dendrimer-based magnetic nanoparticles have presented remarkable potential as carriers in biomedical applications, it is worthwhile to construct a dendrimer-based drug delivery system for cancer treatment. Hence, in the present study, triazine dendrimer functionalized graphene oxide (GO-DT G2.5) was successfully fabricated by the divergent method. Then, the Fe3O4@PEG nanoparticles were attached to the surface of GO-TD G2.5 (GO-TD-Fe3O4@PEG) as a new magnetic nanocarrier for effective loading and the pH-responsive release of Doxorubicin (DOX). The structure and morphology of the synthesized GO-TD-Fe3O4@PEG were characterized by BET, XRD, DLS/ Zeta potential, UV–vis, FT‐IR, AFM, SEM, and VSM analysis. The surface morphology indicated that the average thickness of the sheets in the synthesized nanocarrier had approximately 144.21 nm. The encapsulation efficiency (EE) and drug-loading content (DLC) of this system were obtained ~92.6 and ~9.26%, respectively. The in vitro release studies of DOX from GO-TD-Fe3O4@PEG were performed at various pH values and found that the release process was noticeably controlled pHresponsive behavior. In vitro cytotoxicity studies of the as-synthesized GO-TD-Fe3O4@PEG against normal cell line (MCF-10A) and breast cancer cell line (MCF-7) confirmed that the non-toxic GO-TD-Fe3O4@PEG has excellent biocompatibility. DAPI staining and apoptosis analysis by flow-cytometry demonstrated that the apoptotic effects of GO-TD-Fe3O4@PEG-DOX have higher in comparison to free DOX. Cellular uptake also showed a high uptake percentage for GO-TD-Fe3O4@PEG-DOX than free DOX within 4 h. Therefore, the obtained results in this work suggesting that GO-TD-Fe3O4@PEG nanocomposite is a promising nanocarrier for targeted delivery and controlled release of anticancer drugs for biomedical applications.

PH-Sensitive Alginate/Carboxymethyl Chitosan/Aminated Chitosan Microcapsules for Efficient Encapsulation and Delivery of Diclofenac Sodium.

To develop an effective pH-sensitive drug carrier, alginate (Alg), carboxymethyl chitosan (CMCs), and aminated chitosan (AmCs) derivatives were employed in this study. A simple ionic gelation technique was employed to formulate Alg-CMCs@AmCs dual polyelectrolyte complexes (PECs) microcapsules as a pH-sensitive carrier for efficient encapsulation and release of diclofenac sodium (DS) drug. The developed microcapsules were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), and scanning electron microscope (SEM). The results clarified that formation of dual PECs significantly protected Alg microcapsules from rapid disintegration at colon conditions (pH 7.4), and greatly reduced their porosity. In addition, the dual PECs microcapsules can effectively encapsulate 95.4% of DS-drug compared to 86.3 and 68.6% for Alg and Alg-CMCs microcapsules, respectively. Higher DS-release values were achieved in simulated colonic fluid [SCF; pH 7.4] compared to those obtained in simulated gastric fluid [SGF; pH 1.2]. Moreover, the drug burst release was prevented and a sustained DS-release was achieved as the AmCs concentration increased. The results confirmed also that the developed microcapsules were biodegradable in the presence of the lysozyme enzyme. These findings emphasize that the formulated pH-sensitive microcapsules could be applied for the delivery of diclofenac sodium.

Polymer grafted mesoporous SBA-15 material synthesized via metal-free ATRP as pH-sensitive drug carrier for quercetin

PH-sensitive amphiphilic poly(2-(diethylamino)ethyl methacrylate) (PDEAEMA) were grafted from mesoporous silica molecular sieve SBA-15 surface via metal-free atom transfer radical polymerization (metal-free ATRP). The amino group was introduced onto SBA-15 surface by silane coupling agent KH-550, followed by the ATRP initiator SBA-15-Br was obtained after bromoisobutyryl bromide (BIBB) immobilized onto SBA-15 surface. The PDEAEMA grafted SBA-15 (SBA-15-g-PDEAEMA) inorganic–organic hybrid materials were prepared by surface initiated metal-free ATRP using SBA-15-Br as initiator, 10-phenylphenothiazine (PTH) as photocatalyst, 2-(diethylamino)ethyl methacrylate (DEAEMA) as the monomer. Then, the anticancer drug quercetin was loaded onto SBA-15-g-PDEAEMA hybrid material (SBA-15-g-PDEAEMA-Qu) and the controlled release of quercetin was investigated. The analytical results indicated that the ATRP initiator has been successfully anchored onto the SBA-15 surface and the ordered structure of the mesoporous material has been maintained. The kinetic plots and the curve of the relationship between Mn and monomer conversion illustrates that the polymerization process has the characteristics of “living”/controllable radical polymerization. The TGA results showed that the graft rate of organics in SBA-15 channel is 24.7%. In vitro cytotoxicity evaluation and cell uptake assay results indicated that the cytotoxicity of SBA-15-g-PDEAEMA to the L929 cells had completely disappeared on the 3rd day, SBA-15-g-PDEAEMA has good biocompatibility and can be endocytosed by L929 cells. The drug release rate of SBA-15-g-PDEAEMA hybrid material loaded with quercetin (SBA-15-g-PDEAEMA-Qu) at pH = 5.5 is significantly higher than that at pH = 7.4, the SBA-15-g-PDEAEMA hybrid material can be used as carrier for controlled drug release and has potential application prospects in clinical practice.

In-vitro release study through novel graphene oxide aided alginate based pH-sensitive drug carrier for gastrointestinal tract

Nanomaterials are introduced to drug carriers for enhanced drug loading, improved pH-responsive and, sustained release. Graphene oxide(GO) has gathered significant attention in biomedical applications due to its superior capacity in transporting biomolecules. Authors introduced GO with Calcium alginate(Ca-Alg) to propose a novel drug carrier for gastrointestinal tract with higher encapsulation and sustained release properties. Ciprofloxacin(CIP) has been used as a model drug. Na-Alg and GO concentration, have been optimized based on encapsulation efficiency(EE). The addition of GO improves EE from 75 % to 90 %. An in-vitro drug release study in different environments viz. aqueous, acidic(pH 2.8), and physiological pH(PBS buffer of pH 7.4) to explore the scope of pH-responsive drug delivery. The addition of GO decreases the pore size in Alg-GO, which causes a slower release of drugs in all mediums. In acidic medium, restricted delivery of 60 % drug over 100 h is observed for Alg-GO. In physiological pH, the speedy and gradual release of drugs within 3 h is observed because of the degradation of the polymeric structure.

One-pot hydrothermal synthesis of a magnetic hydroxyapatite nanocomposite for MR imaging and pH-Sensitive drug delivery applications

Synthetic hydroxyapatite (HA) due to its high biocompatibility, anti-inflammatory properties, high stability, and a flexible structure in combination with magnetic nanoparticles has the strong potential to be used in modern medicine including tissue engineering, imaging, and drug delivery. Herein, a hydrothermal process was used to prepare magnetite nanoparticles dispersed on the hydroxyapatite nanorods with cetyltrimethylammonium bromide (CTAB) as a surfactant. Characterization study of the synthesized iron oxide-hydroxyapatite (IO-HA) nanocomposite was performed by FT-IR spectroscopy, X-ray powder diffraction, energy dispersive X-Ray analysis (EDX) for elemental mapping, transmission electron microscopy, and vibrating sample magnetometer. Then, the biocompatibility of the synthesized nanocomposite studied by 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay and hemocompatibility assay. Focus on this point, curcumin loaded IO-HA (Cur@IO-HA) was developed for exploring the pH-sensitivity of the drug carrier and then evaluating its cellular uptake. The in vitro efficacy of the synthesized nanocomposites as a magnetic resonance imaging (MRI) contrast agent was also investigated. Our results showed that IO-HA nanocomposite is non-cytotoxic and hemocompatible as well as a good pH-sensitive drug carrier and a favorable MRI T2 contrast agent. Comparing to the free curcumin, Cur@IO-HA displayed a good cellular uptake. Taking into account the above issues, IO-HA nanocomposite has the most potential for application as a theranostic MRI contrast agent.