Dual Interactions of Amphiphilic Gelatin Copolymer and Nanocurcumin Improving the Delivery Efficiency of the Nanogels

Synthesis and characterization of injectable thermosensitive hydrogel based on Pluronic-grafted silk fibroin copolymer containing hydroxyapatite nanoparticles as potential for bone tissue engineering

Injectable hydrogels are promising for bone tissue engineering due to their minimally invasive application and adaptability to irregular defects. This study presents the development of pluronic grafted silk fibroin (PF-127-g-SF), a temperature-sensitive graft copolymer synthesized from SF and modified PF-127 via a carbodiimide coupling reaction. The PF-127-g-SF copolymer exhibited a higher sol-gel transition temperature (34 °C at 16 % w/v) compared to PF-127 (23 °C), making it suitable for injectable applications. It also showed improved flexibility and strength, with a yielding point increase from <10 % to nearly 30 %. Unlike PF-127 gel, which degrades within 72 h in aqueous media, the PF-127-g-SF copolymer maintained a stable gel structure for over two weeks due to its robust crosslinked hydrogel network. Incorporating hydroxyapatite nanoparticles (n-HA) into the hydrogel reduced pore size and decreased swelling and degradation rates, extending structural stability to four weeks. Increasing n-HA concentration from 0 % to 20 % reduced porosity from 80 % to 66 %. Rheological studies indicated that n-HA enhanced the scaffold's strength and mechanical properties without altering gelation temperature. Cellular studies with MG-63 cells showed that n-HA concentration influenced cell viability and mineralization, highlighting the scaffold's potential in bone tissue engineering.

Fabrication of 3D Printed, Core-and-Shell Implants as Controlled Release Systems for Local siRNA Delivery

The development and clinical translation of small interfering RNA (siRNA) therapies remains challenging owing to their poor pharmacokinetics. 3D printing technology presents a great opportunity to fabricate personalized implants for local and sustained delivery of siRNA. Hydrogels can mimic the mechanical properties of tissues, avoiding the problems associated with rigid implants. Herein, a thermoresponsive composite hydrogel suitable for extrusion 3D-printing is formulated to fabricate controlled-release implants loaded with siRNA-Lipofectamine RNAiMAX complexes. A hydrogel matrix mainly composed of uncharged agarose to protect siRNA from decomplexation is selected. Additionally, pluronic F127 and gelatin are added to improve the printability, degradation, and cell adhesion to the implants. To avoid exposing siRNA to thermal stress during the printing process, a core-and-shell design is set up for the implants in which a core of siRNA-complexes loaded-pluronic F127 is printed without heat and enclosed with a shell comprising the thermoresponsive composite hydrogel. The release profile of siRNA-complexes is envisioned to be controlled by varying the printing patterns. The results reveal that the implants sustain siRNA release for one month. The intactness of the released siRNA-complexes is proven until the eighth day. Furthermore, by changing the printing patterns, the release profiles can be tailored.

Development and optimisation of hydroxyapatite-polyethylene glycol diacrylate hydrogel inks for 3D printing of bone tissue engineered scaffolds

In the event of excessive damage to bone tissue, the self-healing process alone is not sufficient to restore bone integrity. Three-dimensional (3D) printing, as an advanced additive manufacturing technology, can create implantable bone scaffolds with accurate geometry and internal architecture, facilitating bone regeneration. This study aims to develop and optimise hydroxyapatite-polyethylene glycol diacrylate (HA-PEGDA) hydrogel inks for extrusion 3D printing of bone tissue scaffolds. Different concentrations of HA were mixed with PEGDA, and further incorporated with pluronic F127 (PF127) as a sacrificial carrier. PF127 provided good distribution of HA nanoparticle within the scaffolds and improved the rheological requirements of HA-PEGDA inks for extrusion 3D printing without significant reduction in the HA content after its removal. Higher printing pressures and printing rates were needed to generate the same strand diameter when using a higher HA content compared to a lower HA content. Scaffolds with excellent shape fidelity up to 75-layers and high resolution (∼200 µm) with uniform strands were fabricated. Increasing the HA content enhanced the compression strength and decreased the swelling degree and degradation rate of 3D printed HA-PEGDA scaffolds. In addition, the incorporation of HA improved the adhesion and proliferation of human bone mesenchymal stem cells (hBMSCs) onto the scaffolds. 3D printed scaffolds with 2 wt% HA promoted osteogenic differentiation of hBMSCs as confirmed by the expression of alkaline phosphatase activity and calcium deposition. Altogether, the developed HA-PEGDA hydrogel ink has promising potential as a scaffold material for bone tissue regeneration, with excellent shape fidelity and the ability to promote osteogenic differentiation of hBMSCs.

A Closed Loop Stimuli-Responsive Concanavalin A-Loaded Chitosan-Pluronic Hydrogel for Glucose-Responsive Delivery of Short-Acting Insulin Prototyped in RIN-5F Pancreatic Cells

The optimal treatment of diabetes (in particular, type 1 diabetes-T1D) remains a challenge. Closed-loop systems (implants/inserts) provide significant advantages for glucose responsivity and providing real-time sustained release of rapid-acting insulin. Concanavalin A (ConA), a glucose affinity agent, has been used to design closed-loop insulin delivery systems but not without significant risk of leakage of ConA from the matrices and poor mechanical strength of the hydrogels impacting longevity and control of insulin release. Therefore, this work focused on employing a thermoresponsive co-forming matrix between Pluronic F-127 (PL) and structurally robust chitosan (CHT) via EDC/NHS coupling (i.e., covalent linkage of -NH2 from CHT and ConA to the -COOH of PL). The system was characterized for its chemical structure stability and integrity (FTIR, XRD and TGA), injectability, rheological parameters and hydrogel morphology (Texture Analysis, Elastosens TM Bio2 and SEM). The prepared hydrogels demonstrated shear-thinning for injectability with a maximum force of 4.9 ± 8.3 N in a 26G needle with sol-gel transitioning from 25 to 38 °C. The apparent yield stress value of the hydrogel was determined to be 67.47 Pa. The insulin loading efficiency within the hydrogel matrix was calculated to be 46.8%. Insulin release studies revealed glucose responsiveness in simulated glycemic media (4 and 10 mg/mL) over 7 days (97%) (305 nm via fluorescence spectrophotometry). The MTT studies were performed over 72 h on RIN-5F pancreatic cells with viability results >80%. Results revealed that the thermoresponsive hydrogel is a promising alternative to current closed-loop insulin delivery systems.

Gelatin as a bioactive nanodelivery system for functional food applications

Gelatin has long been used as an encapsulant agent in the pharmaceutical and biomedical industries because of its low cost, wide availability, biocompatibility, and degradability. However, the exploitation of gelatin for nanodelivery application is not fully achieved in the functional food filed. In this review article, we highlight the latest work being performed for gelatin-based nanocarriers, including polyelectrolyte complexes, nanoemulsions, nanoliposomes, nanogels, and nanofibers. Specifically, we discuss the applications and challenges of these nanocarriers for stabilization and controlled release of bioactive compounds. To achieve better efficacy, gelatin is frequently used in combination with other biomaterials such as polysaccharides. The fabrication and synergistic effects of the newly developed gelatin composite nanocarriers are also present.

Pluronic® triblock copolymer-based nanoformulations for cancer therapy: A 10-year overview

This paper provides a review of the literature on the use of Pluronic® triblock copolymers for drug encapsulation over the last 10 years. A special focus is given to the progress of drug delivery systems (e.g., micelles, liposomes, micro/nanoemulsions, hydrogels and nanogels, and polymersomes and niosomes); the beneficial aspects of Pluronic® triblock copolymers as biological response modifiers and as pharmaceutical additives, adjuvants, and stabilizers, are also discussed. The advantages and limitations encountered in developing site-specific targeting approaches based on Pluronic-based nanostructures in cancer treatment are highlighted, in addition to innovative examples for improving tumor cytotoxicity while reducing side effects.

Pluronic® F127 Thermoresponsive Viscum album Hydrogel: Physicochemical Features and Cellular In Vitro Evaluation

Viscum album L., popularly known as mistletoe, is well known for its anti-cancer properties, and the pharmaceutical application of hydroalcoholic dry extracts is still limited due to its low solubility in aqueous media, and physicochemical instability. The Pluronic® F127 is an amphiphilic polymer, which permits the solubilization of lipophilic and hydrophilic compounds. In this investigation, physicochemical features of hydrogel containing V. album dry extract (VADE-loaded-hydrogel) were performed by: dynamic light scattering (DLS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). VADE-loaded-hydrogel presented nanometer-size micelles with volume distribution ranging from 10.58 nm to 246.7 nm, and a polydispersity index of 0.441. The sample thermal analyses (TG and DSC) showed similar decomposition curves; however, the thermal events indicated an increase in thermal stability in relation to the presence of the extract. In addition to these interesting pharmaceutical features, IC50 values of 333.40 µg/mL and >1000 µg/mL were obtained when tumor (SCC-25) and non-tumor (L929) cells were incubated with VADE-loaded-hydrogel, respectively. The optical and ultrastructural cellular analysis confirmed the tumor selectivity since the following alterations were detected only in SCC-25 cells: disorganization of plasmatic membrane; an increase of cytoplasmatic vacuole size; alteration in the cristae mitochondrial shape; and generation of amorphous cellular material. These results emphasize the promising antitumoral potential of VADE-loaded-hydrogel as an herbal drug delivery system via in vitro assays.

Antimicrobial Shape Memory Polymer Hydrogels for Chronic Wound Dressings

Chronic wounds can remain open for several months and have high risks of amputation due to infection. Dressing materials to treat chronic wounds should be conformable for irregular wound geometries, maintain a moist wound bed, and reduce infection risks. To that end, we developed cytocompatible shape memory polyurethane-based poly(ethylene glycol) (PEG) hydrogels that allow facile delivery to the wound site. Plant-based phenolic acids were physically incorporated onto the hydrogel scaffolds to provide antimicrobial properties. These materials were tested to confirm their shape memory properties, cytocompatibility, and antibacterial properties. The incorporation of phenolic acids provides a new mechanism for tuning intermolecular bonding in the hydrogels and corollary mechanical and shape memory properties. Phenolic acid-containing hydrogels demonstrated an increased shape recovery ratio (1.35× higher than the control formulation), and materials with cytocompatibility >90% were identified. Antimicrobial properties were retained over 20 days in hydrogels with higher phenolic acid content. Phenolic acid retention and antimicrobial efficacy were dependent upon phenolic acid structures and interactions with the polymer backbone. This novel hydrogel system provides a platform for future development as a chronic wound dressing material that is easy to implant and reduces infection risks.

Curcumin and Paclitaxel co-Loaded Heparin and Poloxamer P403 Hybrid Nanocarrier for Improved Synergistic Efficacy in Breast Cancer

Introduction:

Multi-drug nanosystem has been employed in several therapeutic models due to the synergistic effect of the drugs and/or bioactive compounds, which help in tumor-targeting and limit usual side effects of chemotherapy.

Methods:

In this research, we developed the amphiphilic Heparin-Poloxamer P403 (HSP) nanogel that can load curcumin (CUR) and Paclitaxel (PTX) through the hydrophobic core of Poloxamer P403. The features of HSP nanogel are assessed through Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), differential light scattering (DLS), and critical micelle concentration (CMC). Nanogel and its duel-loaded platform show high stability and spherical morphology.

Results:

The drug release profile indicates fast release at pH 5.5, suggesting effective drug distribution at the tumor site. In vitro research confirms lower cytotoxicity of HSP@CUR@PTX compared with free PTX and higher inhibition effect with MCF-7 than HSP@PTX. These results support the synergism between PTX and CUR.

Conclusion,:

HSP@CUR@PTX suggests a prominent strategy for achieving the synergistic effect of PTX and CUR to circumvent undesirable effects in breast cancer treatment.

Antimutagenic and Antiproliferative Activity of the Coccoloba uvifera L. Extract Loaded in Nanofibers of Gelatin/Agave Fructans Elaborated by Electrospinning

BACKGROUND

The Coccoloba uvifera L. species is currently considered an important source of compounds of high biological value such as lupeol, this is related to different biological activities of importance to human health.

OBJECTIVE

The objective of this study was to encapsulate the C. uvifera extract in nanofibers made with the biopolymers gelatin (G)/high-grade polymerization agave fructans (HDPAF) in the proportions 1:0, 1:1, 1:2, 1:3 and 0:1, through the electrospinning process, in addition to evaluating the antimutagenic and antiproliferative properties of the encapsulated extract.

METHOD

The physicochemical characteristics of the nanofibers were evaluated, as well as the antiproliferative and antimutagenic activities of the encapsulated and unencapsulated extract. SEM evaluation shows nanofibers of smooth, continuous morphology and nanometric size (50-250 nm). The TGA, FTIR-ATR, HPLC-MS analyzes reveal the presence of the extract in the nanofibers.

RESULTS

The extract did not show a mutagenic effect during the development of the Ames test, on the other hand, the MTT test showed the antiproliferative effect at the concentrations of 50 and 100 µg/mL of extract.

CONCLUSION

the extract of C. uvifera loaded in nanofibers elaborated by electrospinning with the G/HDPAF biopolymers, conserves its antimutagenic and antiproliferative properties.

Curcuminoid Co-Loading Platinum Heparin-Poloxamer P403 Nanogel Increasing Effectiveness in Antitumor Activity

Nanosized multi-drug delivery systems provide synergistic effects between drugs and bioactive compounds, resulting in increased overall efficiency and restricted side effects compared to conventional single-drug chemotherapy. In this study, we develop an amphiphilic heparin-poloxamer P403 (HP403) nanogel that could effectively co-load curcuminoid (Cur) and cisplatin hydrate (CisOH) (HP403@CisOH@Cur) via two loading mechanisms. The HP403 nanogels and HP403@CisOH@Cur nanogels were closely analyzed with 1H-NMR spectroscopy, FT-IR spectroscopy, TEM, and DLS, exhibiting high stability in spherical forms. In drug release profiles, accelerated behavior of Cur and CisOH at pH 5.5 compared with neutral pH was observed, suggesting effective delivery of the compounds in tumor sites. In vitro studies showed high antitumor activity of HP403@CisOH@Cur nanogels, while in vivo assays showed that the dual-drug platform prolonged the survival time of mice and prevented tail necrosis. In summary, HP403@CisOH@Cur offers an intriguing strategy to achieve the cisplatin and curcumin synergistic effect in a well-designed delivery platform that increases antitumor effectiveness and overcomes undesired consequences caused by cisplatin in breast cancer treatment.

Advances in the therapeutic delivery and applications of functionalized Pluronics: A critical review

Pluronic (PEO-PPO-PEO) block copolymers can form nano-sized micelles with a structure composed of a hydrophobic PPO core and hydrophilic PEO shell layer. Pluronics are U.S. Food and Drug Administration approved polymers, which are widely used for solubilization of drugs and their delivery, gene/therapeutic delivery, diagnostics, and tissue engineering applications due to their non-ionic properties, non-toxicity, micelle forming ability, excellent biocompatibility and biodegradability. Although Pluronics have been employed as drug carrier systems for several decades, numerous issues such as rapid dissolution, shorter residence time in biological media, fast clearance and weak mechanical strength have hindered their efficacy. Pluronics have been functionalized with pH-sensitive, biological-responsive moieties, antibodies, aptamers, folic acid, drugs, different nanoparticles, and photo/thermo-responsive hydrogels. These functionalization strategies enable Pluronics to act as stimuli responsive and targeted drug delivery vehicles. Moreover, Pluronics have emerged in nano-emulsion formulations and have been utilized to improve the properties of cubosomes, dendrimers and nano-sheets, including their biocompatibility and aqueous solubility. Functionalization of Pluronics results in the significant improvement of target specificity, loading capacity, biocompatibility of nanoparticles and stimuli responsive hydrogels for the promising delivery of a range of drugs. Therefore, this review presents an overview of all advancements (from the last 15 years) in functionalized Pluronics, providing a valuable tool for industry and academia in order to optimize their use in drug or therapeutic delivery, in addition to several other biomedical applications.

Balancing loading, cellular uptake, and toxicity of gelatin-pluronic nanocomposite for drug delivery: Influence of HLB of pluronic

In this study, pluronic stabilized gelatin nanocomposite of varying hydrophilic-lipophilic balance (HLB) were synthesized to study the effect of surface hydrophobicity on their cellular uptake and in turn the delivery of a model hydrophobic bioactive compound, curcumin (CUR). Notably, the variation in HLB from 22 to 8 did not cause much change in morphology (~spherical) and surface charge (~ -6.5 mV) while marginally reducing the size of nanocomposite from 165 ± 097 nm to 134 ± 074 nm. On contrary, nanocomposites exhibited a very significant increase in their numbers, hydrophobicity as well as CUR loading with decreasing HLB values (22-8) of pluronic. Further, the cellular uptake of CUR through pluronic-gelatin nanocomposites was studied in human lung carcinoma (A549) cells. The results indicated that cellular uptake of CUR through nanocomposites followed the order HLB 22 > HLB 18 > HLB 15 > HLB 8. This was also reflected in terms of the decrease in cytotoxicity of CUR through nanocomposite of HLB 8 as compared to that of HLB 22. Interestingly, bare nanocomposite of HLB 8 showed significantly higher cytotoxicity as compared to that of HLB 22. Together these results suggested that although higher hydrophobicity of the gelatin-pluronic nanocomposite facilitated higher entrapment of CUR, the carrier per se became toxic due to its hydrophobic interaction with lipid bilayer of plasma membrane. Thus, HLB parameter is very important in designing hybrid nanocomposite systems involving protein and pluronic to ensure both bio-compatibility of the carrier and the optimum cellular delivery of the pay load.

Block Copolymer Template-Directed Catalytic Systems: Recent Progress and Perspectives

Fabrication of block copolymer (BCP) template-assisted nano-catalysts has been a subject of immense interest in the field of catalysis and polymer chemistry for more than two decades now. Different methods, such as colloidal route, on-substrate methods, bulk self-assembly approaches, combined approaches, and many others have been used to prepare such nano-catalysts. The present review focuses on the advances made in this direction using diblock, triblock, and other types of BCP self-assembled structures. It will be shown how interestingly, researchers have exploited the features of tunable periodicity, domain orientation, and degree of lateral orders of self-assembled BCPs by using fundamental approaches, as well as using different combinations of simple methods to fabricate efficient catalysts. These approaches allow for fabricating catalysts that are used for the growth of single- and multi-walled carbon nanotubes (CNTs) on the substrate, size-dependent electrooxidation of the carbon mono oxide, cracking of 1,3,5-triisopropylbenzene (TIPB), methanol oxidation, formic acid oxidation, and for catalytic degradation of dyes and water pollutants, etc. The focus will also be on how efficient and ease-of-use catalysts can be fabricated using different BCP templates, and how these have contributed to the fabrication of different nano-catalysts, such as nanoparticle array catalysts, strawberry and Janus-like nanoparticles catalysts, mesoporous nanoparticles and film catalysts, gyroid-based bicontinuous catalysts, and hollow fiber membrane catalysts.

Micellar Drug Delivery Systems Based on Natural Biopolymers

The broad diversity of structures and the presence of numerous functional groups available for chemical modifications represent an enormous advantage for the development of safe, non-toxic, and cost-effective micellar drug delivery systems (DDS) based on natural biopolymers, such as polysaccharides, proteins, and peptides. Different drug-loading methods are used for the preparation of these micellar systems, but it appeared that dialysis is generally recommended, as it avoids the formation of large micellar aggregates. Moreover, the preparation method has an important influence on micellar size, morphology, and drug loading efficiency. The small size allows the passive accumulation of these micellar systems via the permeability and retention effect. Natural biopolymer-based micellar DDS are high-value biomaterials characterized by good compatibility, biodegradability, long blood circulation time, non-toxicity, non-immunogenicity, and high drug loading, and they are biodegraded to non-toxic products that are easily assimilated by the human body. Even if some recent studies reported better antitumoral effects for the micellar DDS based on polysaccharides than for commercial formulations, their clinical use is not yet generalized. This review is focused on the studies from the last decade concerning the preparation as well as the colloidal and biological characterization of micellar DDS based on natural biopolymers.

pH-Sensitive nanogels for drug delivery in cancer therapy

Compared to normal tissue, solid tumors exhibit a lower pH value. Such pH gradient can be used to design pH-sensitive nanogels for selective drug delivery. The acid-sensitive elements in the nanogel cause it to swell/degrade rapidly, followed by rapid drug release.

Curcumin-loaded, alginate-gelatin composite fibers for wound healing applications

The wound healing process is characterized by varied biological and molecular cascades including inflammation, tissue proliferation, and remodeling phase. To augment and maintain these cascades, an all-natural matrix system is proposed. Biocompatible biopolymers, sodium alginate and gelatin, were employed to prepare microfibers via extrusion-gelation into a physical crosslinking solution. Curcumin, an anti-inflammatory, anti-oxidant and wound healing agent, was loaded into the fibers as a natural bioactive compound. Curcumin-loaded composite microfibers and blank microfibers were fabricated using biopolymers such as sodium alginate and gelatin. The formulation batches were coded as A1G9-A10G0 according to the varied concentrations of sodium alginate and gelatin. The molecular transitions within the composite microfibers were characterized using FTIR and were further corroborated using molecular mechanics analysis. In mechanical properties tensile strength and elongation-at-break (extensibility) were ranging between 1.08 ± 0.01 to 3.53 ± 0.41 N/mm² and 3.89 ± 0.18 to 0.61 ± 0.03%. The morphological analysis confirmed the formation and fabrication of the microfibers. In addition, physical evaluation including matrix degradation and entrapment efficiency was performed to give a comparative account of various formulations. The water uptake capacity of the blank and curcumin-loaded composite fibers was found to be in the range of 30.77 ± 2.17 to 100.00 ± 5.99 and 22.34 ± 1.11 to 56.34 ± 4.68, respectively. Composite microfibers presented a cumulative release of 85% in 72 h, confirming the prolonged release potential of the composite fibers. The drug release followed an anomalous (non-Fickian) release behavior asserting the role of degradation and diffusion. In an in vivo full-thickness cutaneous wound model, the composite microfibers provided higher degree of contraction 96.89 ± 3.76% as compared to the marketed formulation (Vicco turmeric cream). In conclusion, this all-natural, alginate-gelatin-curcumin composite has the potential to be explored as a cost-effective wound healing platform.

Preparation of Immunotherapy Liposomal-Loaded Thermal-Responsive Hydrogel Carrier in the Local Treatment of Breast Cancer

To reduce the side effects of immune drugs and the sustainable release of immune drugs on local parts, we have designed an injectable thermal-sensitive hydrogel containing an imiquimod-loaded liposome system. In the extracellular environment of tumor tissues (pH 6.4), 50% of the drug was released from the carrier, which could be a result of the morphological changes of the liposomal microstructure in the acidic environment. According to the results in animals, the drug-containing liposomes combined with hydrogel can be effectively applied in breast cancer therapy to delay the growth of tumors as well as to dramatically reduce the death rate of mice.

Nanoencapsulation Enhances Anticoagulant Activity of Adenosine and Dipeptide IleTrp

It is well-known that drugs administered into an organism intravenously or through the gastrointestinal tract are degraded by enzymes of the body, reducing their therapeutic effect. One of the ways to decrease this undesirable process is through the inclusion of drugs in nanomaterials. Earlier strong anticoagulant activity was demonstrated for dipeptide IleTrp (IW) and adenosine (Ado). In this work, the effect of inclusion in nanomaterials on the biological activity of IW and Ado was studied. For this purpose, Ado and IW were incorporated into thermosensitive nanogel composed of pluronic P123-grafted heparin. The prepared nanocarrier was characterized by transmission electron microscopy, dynamic light scattering, and ζ-potential. Biological activity was determined by measuring the bleeding time from mouse tail in vivo and the time of clot formation in vitro. It was found that encapsulation of Ado and IW into nanomaterial significantly increased their effects, resulting in an increase in the bleeding time from mouse tail and clot formation time. Thus, inclusion of low molecular weight anticoagulants Ado and IW into nanomaterials may be considered a way to increase their biological activity.