Photo-triggered caffeic acid delivery via psyllium polysaccharide- gellan gum-based injectable bionanogel for epidermoid carcinoma treatment

Here, the simultaneous effect of chemo- and photothermal therapy against epidermoid carcinoma (EC) was investigated. A novel hydrogel, termed bionanogel (BNG), was designed using psyllium mucilage polysaccharide and bacterial gellan gum, incorporated with nanocomplex carrying caffeic acid (CA) and IR-820, and further characterized. The dual effect of BNG and 808 nm laser (BNG + L) on EC was investigated. Staining and scratch assays were performed to analyze their therapeutic effect on EC. In vivo evaluations of BNG + L in xenograft models were performed. Rapid transition, limited swelling, degradability and high tensile strength indicated BNG stability and sustained drug release. Irradiation with 808 nm laser light at 1.25 W /cm2 for 4 min resulted in a temperature increase of 53 °C and facilitated cell ablation. The in vitro studies showed that BNG + L suppressed cancer progression via a late apoptotic effect. The in vivo study showed that the slow release of CA from BNG + L significantly attenuated EC with low mitotic index and downregulation of proteins involved in cancer proliferation such as EGFR, AKT, PI3K, ERK, mTOR and HIF-1α. Thus, BNG could be a novel medium for targeted and controlled drug delivery for the treatment of epidermoid cancer when triggered by NIR light.

Evaluation of Opuntia-carrageenan superporous hydrogel (OPM-CRG SPH) as an effective biomaterial for drug release and tissue scaffold

The process of wound healing involves complex interplay of systems biology, dependent on coordination of various cell types, both intra and extracellular mechanisms, proteins, and signaling pathways. To enhance these interactions, drugs must be administered precisely and continuously, effectively regulating the intricate mechanisms involved in the body's response to injury. Controlled drug delivery systems (DDS) play a pivotal role in achieving this objective. A proficient DDS shields the wound from mechanical, oxidative, and enzymatic stress, against bacterial contamination ensuring an adequate oxygen supply while optimizing the localized and sustained delivery of drugs to target tissue. A pH-sensitive SPH was designed by blending two natural polysaccharides, Opuntia mucilage and carrageenan, using microwave irradiation and optimized according to swelling index at pH 1.2, 7.0, and 8.0 and % porosity. Optimized grade was analyzed for surface hydrophilicity-hydrophobicity using OCA. Analytical characterizations were performed using FTIR, TGA, XRD, DSC, reflecting semicrystalline behavior. Mechanical property confirmed adequate strength. In vitro drug release study with ciprofloxacin-HCL as model drug showed 97.8 % release within 10 h, fitting to the Korsmeyer-Peppas model following diffusion and erosion mechanism. In vitro antimicrobial, anti-inflammatory assays, zebrafish toxicity, and animal studies in mice with SPH concluded it as a novel biomaterial.

Green Synthesis of Hydrogel-Based Adsorbent Material for the Effective Removal of Diclofenac Sodium from Wastewater

The removal of pharmaceutical contaminants from wastewater has gained considerable attention in recent years, particularly in the advancements of hydrogel-based adsorbents as a green solution for their ease of use, ease of modification, biodegradability, non-toxicity, environmental friendliness, and cost-effectiveness. This study focuses on the design of an efficient adsorbent hydrogel based on 1% chitosan, 40% polyethylene glycol 4000 (PEG4000), and 4% xanthan gum (referred to as CPX) for the removal of diclofenac sodium (DCF) from water. The interaction between positively charged chitosan and negatively charged xanthan gum and PEG4000 leads to strengthening of the hydrogel structure. The obtained CPX hydrogel, prepared by a green, simple, easy, low-cost, and ecological method, has a higher viscosity due to the three-dimensional polymer network and mechanical stability. The physical, chemical, rheological, and pharmacotechnical parameters of the synthesized hydrogel were determined. Swelling analysis demonstrated that the new synthetized hydrogel is not pH-dependent. The obtained adsorbent hydrogel reached the adsorption capacity (172.41 mg/g) at the highest adsorbent amount (200 mg) after 350 min. In addition, the adsorption kinetics were calculated using a pseudo first-order model and Langmuir and Freundlich isotherm parameters. The results demonstrate that CPX hydrogel can be used as an efficient option to remove DCF as a pharmaceutical contaminant from wastewater.

Designing and In Vitro Characterization of pH-Sensitive Aspartic Acid-Graft-Poly(Acrylic Acid) Hydrogels as Controlled Drug Carriers

Acetaminophen is an odorless and white crystalline powder drug, used in the management of fever, pain, and headache. The half-life of acetaminophen is very short; thus, multiple intakes of acetaminophen are needed in a day to maintain a constant pharmacological action for an extended period of time. Certain severe adverse effects are produced due to the frequent intake of acetaminophen, especially hepatotoxicity and skin rashes. Therefore, a drug carrier system is needed which not only prolongs the release of acetaminophen, but also enhances the patient compliance. Therefore, the authors prepared novel aspartic acid-graft-poly(acrylic acid) hydrogels for the controlled release of acetaminophen. The novelty of the prepared hydrogels is based on the incorporation of pH-sensitive monomer acrylic acid with polymer aspartic acid in the presence of ethylene glycol dimethacrylate. Due to the pH-sensitive nature, the release of acetaminophen was prolonged for an extended period of time by the developed hydrogels. Hence, a series of studies was carried out for the formulated hydrogels including sol-gel fraction, FTIR, dynamic swelling, polymer volume analysis, thermal analysis, percent porosity, SEM, in vitro drug release studies, and PXRD analysis. FTIR analysis confirmed the grafting of acrylic acid onto the backbone of aspartic acid and revealed the development of hydrogels. The thermal studies revealed the high thermal stability of the fabricated hydrogels as compared to pure aspartic acid. An irregular surface with a few pores was indicated by SEM. PXRD revealed the amorphous state of the developed hydrogels and confirmed the reduction in the crystallinity of the unreacted aspartic acid by the formulated hydrogels. An increase in gel fraction was observed with the increasing concentration of aspartic acid, acrylic acid, and ethylene glycol dimethacrylate due to the availability of a high amount of free radicals. The porosity study was influenced by the various compositions of developed hydrogels. Porosity was increased due to the enhancement in the concentrations of aspartic acid and acrylic acid, whereas it decreased with the increase in ethylene glycol dimethacrylate concentration. Similarly, the pH-responsive properties of hydrogels were evaluated by dynamic swelling and in vitro drug release studies at two different pH levels (1.2 and 7.4), and a greater dynamic swelling and acetaminophen release were exhibited at pH 7.4 as compared to pH 1.2. An increase in swelling, drug loading, and drug release was seen with the increased incorporation of aspartic acid and acrylic acid, whereas a decrease was detected with the increase in the concentration of ethylene glycol dimethacrylate. Conclusively, the formulated aspartic acid-based hydrogels could be employed as a suitable nonactive pharmaceutical ingredient for the controlled delivery of acetaminophen.

Chitosan crosslinking with pyridoxal 5-phosphate vitamer toward biocompatible hydrogels for in vivo applications

Vitamin B6 is an essential micronutrient in the mammalian diet, with role of coenzyme and synergistic effect with some antibiotics and antitumor drugs. Based on these, we hypothesized that its use for the preparation of hydrogels can yield multifunctional biomaterials suitable for in vivo applications. To this aim, chitosan was reacted with the active form of vitamin B6, pyridoxal 5-phosphate, via acid condensation, when clear hydrogels were obtained. Their investigation by structural characterization methods proved that the hydrogelation was a consequence of both covalent imine formation and physical interactions. The novel hydrogels had microporous morphology and showed shrinking effect in phosphate buffer, indicating good shape preservation and slow dissolution in in vivo environment. Their enzymatic biodegradation could be controlled by the imination degree, varying from 40 to 61% in 21 days. They demonstrated very good in vitro cytocompatibility on normal human dermal fibroblasts cells and no harmful effect on experimental mice, confirming their safely use for in vivo application.

Green Synthesis of pH-Responsive, Self-Assembled, Novel Polysaccharide Composite Hydrogel and Its Application in Selective Capture of Cationic/Anionic Dyes

Dyes are one of the most hazardous chemicals causing significant environmental pollution and affecting water quality. Majority of the existing methods for dye removal and degradation involve synthetic membranes and use of hazardous chemicals, further resulting in secondary pollution. The present study reports polysaccharide based novel composite hydrogel as biodegradable matrix for pH-responsive selective adsorption of cationic/anionic dyes. This membrane showed pH-responsive adsorption of methyl green (MG) and methyl orange (MO) with similar adsorption equilibrium, i.e., 315 and 276 mg g-1, respectively. Interestingly, selective adsorption at different pH has allowed separation of dye mixtures that holds incredible industrial importance for dyes recovery. The hydrogel matrix was able to completely separate MG, a model cationic dye at neutral pH from the dye mixture whereas, it was possible to remove 60% MO, a model anionic dye at acidic pH. Furthermore, comprehensive isothermal and kinetic studies of adsorption revealed that Freundlich isotherm describing the multilayer coverage and pseudo-second-order kinetics were followed. Thermodynamic studies indicated that the adsorption process was spontaneous and endothermic. In fact, the membrane was reusable for at least ten cycles and exhibited desorption efficiency of 80 and 60% for MO and MG, respectively, which may be further recycled to make the process environmentally sustainable. Overall, this study proposes an inexpensive, simple, biologically safe, and efficient adsorbent material for dye effluent treatment.

Formulation and In-Vitro Characterization of pH-Responsive Semi-Interpenetrating Polymer Network Hydrogels for Controlled Release of Ketorolac Tromethamine

Ketorolac tromethamine is a non-steroidal anti-inflammatory drug used in the management of severe pain. The half-life of Ketorolac tromethamine is within the range of 2.5–4 h. Hence, repeated doses of Ketorolac tromethamine are needed in a day to maintain the therapeutic level. However, taking several doses of Ketorolac tromethamine in a day generates certain complications, such as acute renal failure and gastrointestinal ulceration. Therefore, a polymeric-controlled drug delivery system is needed that could prolong the release of Ketorolac tromethamine. Therefore, in the current study, pH-responsive carbopol 934/sodium polystyrene sulfonate-co-poly(acrylic acid) (CP/SpScPAA) hydrogels were developed by the free radical polymerization technique for the controlled release of Ketorolac tromethamine. Monomer acrylic acid was crosslinked with the polymers carbopol 934 and sodium polystyrene sulfonate by the cross-linker N’,N’-methylene bisacrylamide. Various studies were conducted to evaluate and assess the various parameters of the fabricated hydrogels. The compatibility of the constituents used in the preparation of hydrogels was confirmed by FTIR analysis, whereas the thermal stability of the unreacted polymers and developed hydrogels was analyzed by TGA and DSC, respectively. A smooth and porous surface was indicated by SEM. The crystallinity of carbopol 934, sodium polystyrene sulfonate, and the prepared hydrogels was evaluated by PXRD, which revealed a reduction in the crystallinity of reactants for the developed hydrogels. The pH sensitivity of the polymeric hydrogel networks was confirmed by dynamic swelling and in vitro release studies with two different pH media i.e., pH 1.2 and 7.4, respectively. Maximum swelling was exhibited at pH 7.4 compared to pH 1.2 and, likewise, a greater percent drug release was perceived at pH 7.4. Conclusively, we can demonstrate that the developed pH-sensitive hydrogel network could be employed as a suitable carrier for the controlled delivery of Ketorolac tromethamine.

In vitro and in vivo study of pH-sensitive and colon-targeting P(LE-IA-MEG) hydrogel microspheres used for ulcerative colitis therapy

Hydrocortisone sodium succinate (HSS) is an anti-inflammatory drug, but its application on ulcerative colitis (UC) treatment is limited by its associated side-effects. To solve this problem, a kind of pH-sensitive P(LE-IA-MEG) hydrogel microspheres (HMSs) were prepared as the drug carrier of hydrocortisone sodium succinate (HSS) for the treatment of UC. The P(LE-IA-MEG) HMSs were spherical in shape with good dispersion and the mean particle size was 34.87±0.90μm. HSS was successfully loaded into the P(LE-IA-MEG) HMSs. The in vitro release study of HSS-loaded HMSs (HSS-HMSs) revealed that the HSS-HMSs possessed desirable pH-sensitivity, the cumulative release rate was 4.07% and 94.64% in the solution with pH 1.2 and pH 7.4 solution during 12h, respectively. Furthermore, the study on pharmacokinetic, gastrointestinal drug residue and side-effects were conducted to evaluate the in vivo colon-targeting property of the HSS-HMSs. All the results showed that the HSS-HMSs could deliver HSS to the colon as well as reduce its premature absorption in the upper gastrointestinal tract. Finally, the HSS-HMSs showed better ameliorative effects and therapeutic effects on mice with experimental colitis as compared to HSS. In conclusion, the HSS-HMSs had great potential in the treatment of UC.

Engineered Hydrogels for Local and Sustained Delivery of RNA-Interference Therapies

It has been nearly two decades since RNA-interference (RNAi) was first reported. While there are no approved clinical uses, several phase II and III clinical trials suggest the great promise of RNAi therapeutics. One challenge for RNAi therapies is the controlled localization and sustained presentation to target tissues, to both overcome systemic toxicity concerns and to enhance in vivo efficacy. One approach that is emerging to address these limitations is the entrapment of RNAi molecules within hydrogels for local and sustained release. In these systems, nucleic acids are either delivered as siRNA conjugates or within nanoparticles. A plethora of hydrogels has been implemented using these approaches, including both traditional hydrogels that have already been developed for other applications and new hydrogels developed specifically for RNAi delivery. These hydrogels have been applied to various applications in vivo, including cancer, bone regeneration, inflammation and cardiac repair. This review will examine the design and implementation of such hydrogel RNAi systems and will cover the most recent applications of these systems.

Stimulus responsive nanogel with innate near IR fluorescent capability for drug delivery and bioimaging

A brighter, non toxic and biocompatible optical imaging agent is one of the major quests of biomedical research. Here in, we report a photoluminescent comacromer [PEG-poly(propylene fumarate)-citric acid-glycine] and novel stimulus (pH) responsive nanogel endowed with excitation wavelength dependent fluorescence (EDF) for combined drug delivery and bioimaging applications. The comacromer when excited at different wavelengths in visible region from 400nm to 640nm exhibits fluorescent emissions from 510nm to 718nm in aqueous condition. It has high Stokes shift (120nm), fluorescent lifetime (7 nanoseconds) and quantum yield (50%). The nanogel, C-PLM-NG, prepared with this photoluminescent comacromer and N,N-dimethyl amino ethylmethacrylate (DMEMA) has spherical morphology with particle size around 100nm and 180nm at pH 7.4 (physiological) and 5.5 (intracellular acidic condition of cancer cells) respectively. The studies on fluorescence characteristics of C-PLM NG in aqueous condition reveal large red-shift with emissions from 523nm to 700nm for excitations from 460nm to 600nm ascertaining the EDF characteristics. Imaging the near IR emission with excitation at 535nm was accomplished using cut-off filters. The nanogel undergoes pH responsive swelling and releases around 50% doxorubicin (DOX) at pH 5.5 in comparison with 15% observed at pH 7.4. The studies on in vitro cytotoxicity with MTT assay and hemolysis revealed that the present nanogel is non-toxic. The DOX-loaded C-PLM-NG encapsulated in Hela cells induces lysis of cancer cells. The inherent EDF characteristics associated with C-PLM NG enable cellular imaging of Hela cells. The studies on biodistribution and clearance mechanism of C-PLM-NG from the body of mice reveal bioimaging capability and safety of the present nanogel. This is the first report on a polymeric nanogel with innate near IR emissions for bioimaging applications.

Modified biopolymer-dextrin based crosslinked hydrogels: application in controlled drug delivery

This review describes hydrogels and their classifications along with the synthesis and properties of biopolymer-dextrin based crosslinked hydrogels towards potential application in controlled drug delivery.

Hybrid polypeptide hydrogels produced via native chemical ligation

The NCL crosslinked hybrid hydrogels composed of poly(γ-glutamic acid) and ε-poly-lysine have good biocompatibility and tunable properties.

Assessment of the drug loading, in vitro and in vivo release behavior of novel pH-sensitive hydrogel

CONTEXT

As a glucocorticoid drug, dexamethasone has good therapeutic effects for ulcerative colitis. pH-sensitive hydrogels could make conventional changes of volume in response with different pH values. Meanwhile, they could load drugs depending on its internal three-dimensional network structure.

OBJECTIVE

Appropriate methods were used to improve the drug-loading capacity of hydrogel and exploring the colon-targeting character of dexamethasone hydrogel.

MATERIALS AND METHODS

Different solvents (ethanol and 1,2-propanediol) were employed to dissolve dexamethasone as well as hydrogel monomer materials (poly(ethylene glycol) methyl ether (MPEG)-poly(lactide acid)-acryloyl chloride macromonomer, itaconic acid (IA) and MPEG-methacrylate), then mixing them together to prepare hydrogel through the heat-initiated free radical polymerization method. Differential scanning calorimetry and X-ray diffraction methods were used to verify whether dexamethasone was loaded into hydrogels. In vitro drug release behavior and in vivo pharmacokinetic study were also investigated in detail.

RESULTS

Dexamethasone was successfully loaded into hydrogel, and its loading capacity was improved (5 mg/g). Both the in vitro release study and the in vivo pharmacokinetic study showed the good colon-targeting character of the pH-sensitive P(LE-IA-MEG) hydrogel (T max = 1.0 h, C max = 2.16 µg/ml of dexamethasone; T max = 3.9 h, C max = 0.43 µg/ml of dexamethasone hydrogel).

DISCUSSION

Dexamethasone could be targeted to the colon site by P(LE-IA-MEG) hydrogel, thereby improving its therapeutic effect and reduce its side effects.

CONCLUSION

P(LE-IA-MEG) hydrogel might have great potential application in colon-targeted drug delivery systems.

Polymer-based stimuli-responsive nanosystems for biomedical applications

The application of organic polymers and inorganic/organic hybrid systems in numerous fields of biotechnology has seen a considerable growth in recent years. Typically, organic polymers with diverse structures, compositional variations and differing molecular weights have been utilized to assemble polymeric nanosystems such as polymeric micelles, polymersomes, and nanohydrogels with unique features and structural properties. The architecture of these polymeric nanosystems involves the use of both hydrophobic and hydrophilic polymeric blocks, making them suitable as vehicles for diagnostic and therapeutic applications. Recently, "smart" or "intelligent" polymers have attracted significant attention in the biomedical field wherein careful introduction of specific polymeric modalities changes a banal polymeric nanosystem to an advanced stimuli-responsive nanosystem capable of performing extraordinary functions in response to an internal or external trigger such as pH, temperature, redox, enzymes, light, magnetic, or ultrasound. Further, incorporation of inorganic nanoparticles such as gold, silica, or iron oxide with surface-bound stimuli-responsive polymers offers additional advantages and multifunctionality in the field of nanomedicine. This review covers the physical properties and applications of both organic and organic/inorganic hybrid nanosystems with specific recent breakthroughs in drug delivery, imaging, tissue engineering, and separations and provides a brief discussion on the future direction.