Encapsulation of the growth factor neurotrophin-3 in heparinised poloxamer hydrogel stabilises bioactivity and provides sustained release.

Poloxamer-based hydrogels show promise to stabilise and sustain the delivery of growth factors in tissue engineering applications, such as following spinal cord injury. Typically, growth factors such as neurotrophin-3 (NT-3) degrade rapidly in solution. Similarly, poloxamer hydrogels also degrade readily and are, therefore, only capable of sustaining the release of a payload over a small number of days. In this study, we focused on optimising a hydrogel formulation, incorporating both poloxamer 188 and 407, for the sustained delivery of bioactive NT-3. Hyaluronic acid blended into the hydrogels significantly reduced the degradation of the gel. We identified an optimal hydrogel composition consisting of 20 % w/w poloxamer 407, 5 % w/w poloxamer 188, 0.6 % w/w NaCl, and 1.5 % w/w hyaluronic acid. Heparin was chemically bound to the poloxamer chains to enhance interactions between the hydrogel and the growth factor. The unmodified and heparin-modified hydrogels exhibited sustained release of NT-3 for 28 days while preserving the bioactivity of NT-3. Moreover, these hydrogels demonstrated excellent cytocompatibility and had properties suitable for injection into the intrathecal space, underscoring their suitability as a growth factor delivery system. The findings presented here contribute valuable insights to the development of effective delivery strategies for therapeutic growth factors for tissue engineering approaches, including the treatment of spinal cord injury.

Thermally-responsive and reduced glutathione-sensitive folate-targeted nanocarrier based on alginate and pluronic F127 for on-demand release of methotrexate.

A specific rheumatoid arthritis (RA)-microenvironment-triggered nanocarrier for RA treatment of a first-line antirheumatic drug (Methotrexate, MTX) has been proposed. Reduced glutathione (GSH) responsivity, cystamine, was first introduced on the alginate backbone, which was then used as the bridge to connect pluronic F127 (temperature-responsive factor) and folic acid (targeting factor for active immune cells), resulting in dual-responsive triggered targeting carrier, PCAC-FA. In vitro study demonstrated that PCAC-FA was preferentially taken up by activated macrophage cells rather than normal ones, suggesting the targeting of PCAC-FA to inflamed tissue. The loading capacity of the designed carrier was 21.23 ± 0.91 %. MTX from the PCAC-FA carrier was significantly accelerated release in the presentation of glutathione or in cold shock condition, proposing the efficacy-controlled release. MTX@PCAC-FA showed excellent hemocompatibility, confirming a suitable application with parenteral administration. Notably, the acute and subacute toxicity in the mice model showed that the toxicity of MTX had significantly reduced after encapsulating in the PCAC-FA carrier. These nanoplatforms not only provide an alternative safe strategy for the clinical treatment of rheumatoid arthritis with MTX but also deliver MTX selectively and provide on-demand drug release via external and internal signals, thus emerging as a promising therapeutic option for precise RA therapy.

Fabrication of carboxymethyl cellulose-based thermo-sensitive hydrogels and inhibition of corneal neovascularization.

Corneal neovascularization (CNV) is a common multifactorial sequela of anterior corneal segment inflammation, which could lead to visual impairment and even blindness. The main treatments available are surgical sutures and invasive drug injections, which could cause serious ocular complications. To solve this problem, a thermo-sensitive drug-loaded hydrogel with high transparency was prepared in this study, which could achieve the sustained-release of drugs without affecting normal vision. In briefly, the thermo-sensitive hydrogel (PFNOCMC) was prepared from oxidized carboxymethyl cellulose (OCMC) and aminated poloxamer 407 (PF127-NH2). The results proved the PFNOCMC hydrogels possess high transparency, suitable gel temperature and time. In the CNV model, the PFNOCMC hydrogel loading bone morphogenetic protein 4 (BMP4) showed significant inhibition of CNV, this is due to the hydrogel allowed the drug to stay longer in the target area. The animal experiments on the ocular surface were carried out, which proved the hydrogel had excellent biocompatibility, and could realize the sustained-release of loaded drugs, and had a significant inhibitory effect on the neovascularization after ocular surface surgery. In conclusion, PFNOCMC hydrogels have great potential as sustained-release drug carriers in the biomedical field and provide a new minimally invasive option for the treatment of neovascular ocular diseases.

Evaluation of antimicrobial photodynamic action of a pluronic and pectin based film loaded with methylene blue against methicillin resistantStaphylococcus aureus.

Antimicrobial wound dressings play a crucial role in treatment of wound infections. However, existing commercial options fall short due to antibiotic resistance and the limited spectrum of activity of newly emerging antimicrobials against bacteria that are frequently encountered in wound infections. Antimicrobial photodynamic therapy (aPDT) is very promising alternative therapeutic approach against antibiotic resistant microbes such as methicillin resistantStaphylococcus aureus (MRSA). However, delivery of the photosensitizer (PS) homogeneously to the wound site is a challenge. Though polymeric wound dressings based on synthetic and biopolymers are being explored for aPDT, there is paucity of data regarding theirin vivoefficacy. Moreover, there are no studies on use of PS loaded, pluoronic (PL) and pectin (PC) based films for aPDT. We report development of a polymeric film for potential use in aPDT. The film was prepared using PL and PC via solvent casting approach and impregnated with methylene blue (MB) for photodynamic inactivation of MRSAin vitroandin vivo. Atomic force microscopic imaging of the films yielded vivid pictures of surface topography, with rough surfaces, pores, and furrows. The PL:PC ratio (2:3) was optimized that would result in an intact film but exhibit rapid release of MB in time scale suitable for aPDT. The film showed good antibacterial activity against planktonic suspension, biofilm of MRSA upon exposure to red light. Investigations on MRSA infected excisional wounds of mice reveal that topical application of MB loaded film for 30 min followed by red light exposure for 5 min (fluence; ∼30 J cm-2) or 10 min (fluence; ∼60 J cm-2) reduces ∼80% or ∼92% of bioburden, respectively. Importantly, the film elicits no significant cytotoxicity against keratinocytes and human adipose derived mesenchymal stem cells. Taken together, our data demonstrate that PS-loaded PL-PC based films are a promising new tool for treatment of MRSA infected wounds.

Number of previous surgeries and antibiotic resistance decreases the success of local administration of antibiotic-impregnated poloxamer 407 hydrogel when managing orthopedic surgical site infections in dogs.

OBJECTIVE: To report the outcome of locally administered antibiotic-impregnated poloxamer 407 (P407) hydrogel in dogs diagnosed with orthopedic surgical site infections (SSIs) and to identify risk factors for treatment failure. ANIMALS: 34 client-owned dogs diagnosed with an orthopedic surgical site infection treated with local antibiotic-impregnated P407 hydrogel. PROCEDURES: Medical records were reviewed of dogs receiving antibiotic-impregnated P407 hydrogel for an active orthopedic SSI between March 2018 and December 2020. The rate of successful infection clearance was calculated. Risk factors for failed treatment were evaluated with statistical analyses. RESULTS: 34 dogs met the inclusion criteria. Vancomycin-impregnated P407 hydrogel (20 mg/mL) was implanted in all dogs. The rate of infection clearance was 77%. Each unit increase in the number of surgeries performed at a site before gel implantation decrease the chance of successful infection clearance by 25% (P = .005; unit OR, 0.25; 95% CI, 0.08 to 0.81). Presence of multidrug or methicillin resistance increased risk for treatment failure by 7.69 times (P = .042; OR, 0.13; 95% CI, 0.01 to 1.14). No adverse events related to gel administration were seen. CLINICAL RELEVANCE: Treatment outcomes were negatively impacted by the presence of multidrug or methicillin resistance and by an increased number of surgeries before gel implantation. Local administration of antibiotic-impregnated P407 hydrogel had a high success rate with no adverse effects in this population. Local antibiotic gel administration may improve treatment outcomes in dogs with complicated SSI.

A topical thermosensitive hydrogel system with cyclosporine A PEG-PCL micelles alleviates ulcerative colitis induced by TNBS in mice.

Ulcerative colitis (UC) is an idiopathic, chronic, relapsing disease. In most cases, only the distal colon is affected, and the colonic stasis or fast colonic transit through the inflamed colon usually results in reduced exposure of the distal inflamed colon. Although the immunosuppressant cyclosporine A (CsA) has been used in patients with severe colitis who do not respond to corticosteroids, the clinical application of CsA remains limited due to the systemic toxicities and insufficient accumulation at the site of action for the intravenous and oral routes. In this study, we loaded CsA into the amphipathic poly(ethylene glycol)-poly(ε-caprolactone) (PEG-PCL) micelles and then embedded them in hydrogels consisting of chitosan, poloxamer 188, and poloxamer 407 to construct a thermosensitive and mucoadhesive hydrogel drug delivery system (PLCP). The PLCP presented a high drug-loading capacity and showed a stable and rapid gelation rate after rectal administration into the body. Compared to CsA-loaded micelles and Sandimmun (Neoral®), the developed thermosensitive gel exhibited prolonged retention on the inflamed colon, as seen from in vitro adhesion and in vivo distribution experiments. It also fast mitigated colitis symptoms in TNBS-treated mice by regulating the expression levels of proinflammatory cytokines (TNF-α, IL-1ß, COX-2, and iNOS2), anti-inflammatory cytokines (IL-10, Nrf2, NQO1, and HO-1), and other relevant biochemical factors. Our results suggested that CsA-loaded micelle thermal hydrogel system could be a promising strategy by enhancing the retention in the diseased colon and promoting the relief and recovery of UC.

Chitosan-poly(lactide-co-glycolide)/poloxamer mixed micelles as a mucoadhesive thermo-responsive moxifloxacin eye drop to improve treatment efficacy in bacterial keratitis.

A mucoadhesive self-assembling polymeric system was developed to carry moxifloxacin (M) for treating bacterial keratitis (BK). Chitosan-PLGA (C) conjugate was synthesized, and poloxamers (F68/127) were mixed in different proportions (1: 5/10) to prepare moxifloxacin (M)-encapsulated mixed micelles (M@CF68/127(5/10)Ms), including M@CF68(5)Ms, M@CF68(10)Ms, M@CF127(5)Ms, and M@CF127(10)Ms. The corneal penetration and mucoadhesiveness were determined biochemically, in vitro using human corneal epithelial (HCE) cells in monolayers and spheroids, ex vivo using goat cornea, and in vivo via live-animal imaging. The antibacterial efficacy was studied on planktonic biofilms of P. aeruginosa and S. aureus (in vitro) and Bk-induced mice (in vivo). Both M@CF68(10)Ms and M@CF127(10)Ms demonstrated high cellular uptake, corneal retention, muco-adhesiveness, and antibacterial effect, with M@CF127(10)Ms exhibiting superior therapeutic effects in P. aeruginosa and S. aureus-infected BK mouse model by reducing the corneal bacterial load and preventing corneal damage. Therefore, the newly developed nanomedicine is promising for clinical translation in treating BK.

zwitterionic Pluronic analog-coated PLGA nanoparticles for oral insulin delivery.

In recent years, zwitterionic materials have drawn great attention in oral drug delivery system due to their capacity for rapid mucus diffusion and enhanced cellular internalization. However, zwitterionic materials tend to show strong polarity that was hard to directly coat hydrophobic nanoparticles (NPs). Inspired by Pluronic coating, a simple and convenient strategy to coat NPs with zwitterionic materials using zwitterionic Pluronic analogs was developed in this investigation. Poly(carboxybetaine)-poly(propylene oxide)-Poly(carboxybetaine) (PCB-PPO-PCB, PPP), containing PPO segments with MW > 2.0 kDa, can effectively adsorb on the surface of PLGA NPs with typical core-shell spherical in shape. The PLGA@PPP4K NPs were stable in gastrointestinal physiological environment and sequentially conquered mucus and epithelium barriers. Proton-assisted amine acid transporter 1 (PAT1) was verified to contribute to the enhanced internalization of PLGA@PPP4K NPs, and the NPs could partially evade lysosomal degradation pathway and utilize retrograde pathway for intracellular transport. In addition, the enhanced villi absorption in situ and oral liver distribution in vivo were also observed compared to PLGA@F127 NPs. Moreover, insulin-loaded PLGA@PPP4K NPs as an oral delivery application for diabetes induce a fine hypoglycemic response in diabetic rats after oral administration. The results of this study demonstrated that zwitterionic Pluronic analogs-coated NPs might provide a new perspective for zwitterionic materials application as well as oral delivery of biotherapeutics.

Nasal administration of a temozolomide-loaded thermoresponsive nanoemulsion reduces tumor growth in a preclinical glioblastoma model.

Glioblastoma (GB) is the worst and most common primary brain tumor. Temozolomide (TMZ), an alkylating agent, is widely used for treating primary and recurrent high-grade gliomas. However, at least 50% of TMZ treated patients do not respond to TMZ and the development of chemoresistance is a major problem. Here, we designed a lipid nanoemulsion containing a thermoresponsive polymer (poloxamer 407) aiming to improve TMZ release into the brain via nasal delivery. Increasing amounts of poloxamer 407 were added to preformed nanoemulsions (250 nm-range) obtained by spontaneous emulsification. The influence of the polymer concentration (from 2.5% to 12.5%) and temperature on viscosity was clearly evidenced. Such effect was also noticed on the mucoadhesiveness of formulations, as well as TMZ release rate and retention/permeation through nasal porcine mucosa using Franz-type diffusion cells. From these results, a formulation containing 10% of poloxamer (NTMZ-P10) was selected for further experiments by nasal route. A significantly higher TMZ amount was observed in the brain of rats from NTMZ-P10 in comparison with controls. Finally, our results show that formulation reduced significantly tumor growth by three-fold: 103.88 ± 43.67 mm3 (for NTMZ-P10) and 303.28 ± 95.27 mm3 (control). Overall, these results suggest the potential of the thermoresponsive formulation, administered by the non-invasive nasal route, as a future effective glioblastoma treatment.

RGD-decorated PLGA nanoparticles improved effectiveness and safety of cisplatin for lung cancer therapy.

Upon extensive pharmaceutical and biomedical research to treat lung cancer indicates that lung cancer remains one of the deadliest diseases and the leading cause of death in men and women worldwide. Lung cancer remains untreated and has a high mortality rate due to the limited potential for effective treatment with existing therapies. This highlights the urgent need to develop an effective, precise and sustainable solutions to treat lung cancer. In this study, we developed RGD receptor-targeted PLGA nanoparticles for the controlled and targeted co-delivery of cisplatin (CDDP) and upconversion nanoparticles (UCNP) in lung cancer therapy. Pluronic F127-RGD conjugate was synthesized by carbodiimide chemistry method and the conjugation was confirmed by FTIR and 1HNMR spectroscopy techniques. PLGA nanoparticles were developed by the double emulsification method, then the surface of the prepared nanoparticles was decorated with Pluronic F127-RGD conjugate. The prepared formulations were characterized for their particle size, polydispersity index, zeta potential, surface morphology, drug encapsulation efficiency, and in vitro drug release and haemolysis studies. Pharmacokinetic studies and safety parameters in BAL fluid were assessed in rats. Histopathology of rat lung tissue was performed. The obtained results of particle sizes of the nanoparticle formulations were found 100-200 nm, indicating the homogeneity of dispersed colloidal nanoparticles formulations. Transmission Electron Microscopy (TEM) revealed the spherical shape of the prepared nanoparticles. The drug encapsulation efficiency of PLGA nanoparticles was found to range from 60% to 80% with different nanoparticles counterparts. RGD receptor-targeted PLGA nanoparticles showed controlled drug release for up to 72 h. Further, RGD receptor-targeted PLGA nanoparticles achieved higher cytotoxicity in compared to CFT, CFT, and Ciszest-50 (marketed CDDP injection). The pharmacokinetic study revealed that RGD receptor-targeted PLGA nanoparticles were 4.6-fold more effective than Ciszest-50. Furthermore, RGD receptor-targeted PLGA nanoparticles exhibited negligible damage to lung tissue, low systemic toxicity, and high biocompatible and safety in lung tissue. The results of RGD receptor-targeted PLGA nanoparticles indicated that it is a promising anticancer system that could further exploited as a potent therapeutic approach for lung cancer.

Efficacy of a local anesthetic gel infusion kit for pain relief after minimally invasive colorectal surgery: an open-label, randomized clinical trial.

Continuous wound infusion with local anesthesia is an effective method for reducing postoperative pain after laparoscopic colorectal surgery. However, most subcutaneous local anesthesia is delivered through continuous injection, which can be inconvenient for patients. This study compared the effectiveness of postoperative pain relief from the application of a local poloxamer 407-based ropivacaine hydrogel (Gel) to the incision site with continuous infusion-type ropivacaine administration (On-Q) in patients undergoing laparoscopic colorectal surgery. This prospective, randomized, non-inferiority study included 61 patients who underwent laparoscopic colorectal surgery with an incision length of 3-6 cm. All 61 patients were randomly assigned to the Gel group (poloxamer 407-based 0.75% ropivacaine, 22.5 mg) or the On-Q group (0.2% ropivacaine, 4 mg/hour for two days). Postoperative analgesia was induced in all patients with intravenous patient-controlled analgesia (IV-PCA). The outcome measures, which were assessed for 72 h after surgery, included the total amount of fentanyl consumed via IV-PCA (primary endpoint), and the amount of rescue analgesia (pethidine) and postoperative pain intensity assessed using a numeric rating scale (NRS) [secondary endpoints]. The Gel was administered to 31 patients and On-Q was used for 30 patients. There was no significant difference in the total usage of fentanyl between the two groups (Gel group, 1623.98 mcg; On-Q group, 1595.12 mcg; P = 0.806). There was also no significant difference in the frequency of analgesic rescue medication use (P = 0.213) or NRS scores (postoperative 6 h, P = 0.860; 24 h, P = 0.333; 48 h, P = 0.168; and 72 h, P = 0.655) between the two groups. The Gel, which continuously delivers a local anesthetic to operative sites, can thus be considered an effective device for analgesia and pain relief for midline incisions in laparoscopic colorectal surgery.

Preclinical development of carrier-free prodrug nanoparticles for enhanced antitumor therapeutic potential with less toxicity.

BACKGROUND: Nanomedicine has emerged as a promising strategy for cancer treatment. The most representative nanomedicine used in clinic is PEGylated liposomal doxorubicin DOXIL®, which is first FDA-approved nanomedicine. However, several shortcomings, such as low drug loading capacity, low tumor targeting, difficulty in mass production and potential toxicity of carrier materials, have hindered the successful clinical translation of nanomedicines. In this study, we report a preclinical development process of the carrier-free prodrug nanoparticles designed as an alternative formulation to overcome limitations of conventional nanomedicines in the terms of technical- and industrial-aspects. RESULTS: The carrier-free prodrug nanoparticles (F68-FDOX) are prepared by self-assembly of cathepsin B-specific cleavable peptide (FRRG) and doxorubicin (DOX) conjugates without any additional carrier materials, and further stabilized with Pluronic F68, resulting in high drug loading (> 50%). The precise and concise structure allow mass production with easily controllable quality control (QC), and its lyophilized powder form has a great long-term storage stability at different temperatures (- 4, 37 and 60 °C). With high cathepsin B-specificity, F68-FDOX induce a potent cytotoxicity preferentially in cancer cells, whereas their cytotoxicity is greatly minimized in normal cells with innately low cathepsin B expression. In tumor models, F68-FDOX efficiently accumulates within tumor tissues owing to enhanced permeability and retention (EPR) effect and subsequently release toxic DOX molecules by cathepsin B-specific cleavage mechanism, showing a broad therapeutic spectrum with significant antitumor activity in three types of colon, breast and pancreatic cancers. Finally, the safety of F68-FDOX treatment is investigated after single-/multi-dosage into mice, showing greatly minimized DOX-related toxicity, compared to free DOX in normal mice. CONCLUSIONS: Collectively, these results provide potential preclinical development process of an alternative approach, new formulation of carrier-free prodrug nanoparticles, for clinical translation of nanomedicines.

pH/Thermosensitive dual-responsive hydrogel based sequential delivery for site-specific acute limb ischemia treatment.

Acute limb ischemia (ALI) is the most severe manifestation of peripheral artery disease, accompanied by pH/temperature-microenvironment changes in two different phases. In the acute phase, temperature and pH are significantly decreased, and reactive oxygen species (ROS) are excessively generated owing to the sharp reduction of blood perfusion. Afterwards, in the chronic phase, although the temperature gradually recovers, angiogenesis is delayed due to chronic vascular injury, skeletal muscle cell apoptosis and endothelial cell dysfunction. Current therapeutic strategies mainly focus on recanalization; however, their effects on scavenging ROS in the acute phase and promoting angiogenesis in the chronic phase are quite limited. Herein, an injectable pH and temperature dual-responsive poloxamer 407 (PF127)/hydroxymethyl cellulose (HPMC)/sodium alginate (SA)-derived hydrogel (FHSgel), encapsulating melatonin and diallyl trisulfide-loaded biodegradable hollow mesoporous silica nanoparticles (DATS@dHMSNs), is developed, which can intelligently respond to the different phases of ALI. In the acute phase of ischemia, the decreased pH results in the rapid release of melatonin to scavenge excessive ischemia-induced ROS. On the other hand, in the chronic repair phase, the recovered temperature triggers the sustained release of DATS@dHMSNs from the FHSgel, thus generating hydrogen sulfide (H2S) to enhance the angiogenesis and microcirculation reconstruction of ischemic limbs.

A TGF-α and TGF-ß1 Poloxamer-based micelle/hydrogel composite: A promising novel candidate for the treatment of anosmia.

Anosmia is the inability to smell or loss of the sense of smell. It can reduce your ability to detect the smell of smoke, gas leaks, or spoiled food, as well as hinder the quality of life related to social interactions and feelings of well-being. In the current study, a drug delivery composite was designed to cure anosmia and its efficiency in delivering transforming growth factor alpha (TGF-α) and transforming growth factor beta 1 (TGF-ß1) to the nasal cavity was evaluated. Bovine serum albumin (BSA) was used as a model protein for encapsulation into Poloxamers 407 micelles. For the optimization of the BSA-micelle formulation, a two-parameter five-level central composite design (CCD) was applied. The BSA-micelle was optimized with a particle size of 41 nm, drug loading of 8%, and encapsulation efficiency of 74%. Further, the BSA-micelle was characterized by FESEM, TEM, and FTIR. The analysis of release profile suggested high-paced free BSA release compared to the gradual and prolonged release of BSA-micelle/hydrogel and BSA-micelles. The cytotoxicity assay demonstrated the safety of TGF-α and TGF-ß1-micelles/hydrogel. Moreover, it was observed that TGF-α and TGF-ß1 within the hydrogels promote cellular viability and human olfactory ectomesenchymal stem cell OE-MSCs proliferation. In conclusion, According to the results of our study, the TGF-α and TGF-ß1-micelle/hydrogel-based delivery system provides a suitable alternative for anosmia treatment.

Mucus-Penetrating Silk Fibroin-Based Nanotherapeutics for Efficient Treatment of Ulcerative Colitis.

Oral nanoparticles have been considered a prospective drug delivery carrier against ulcerative colitis (UC). To enhance the mucus-penetrating capacity and aqueous solubility, and strengthen the anti-inflammatory effect of resveratrol (RSV), we fabricated RSV-loaded silk fibroin-based nanoparticles with the functionalization of Pluronic F127 (PF-127). The obtained PF-127-functionalized RSV-loaded NPs had an average particle size around 170 nm, a narrow size distribution (polydispersity index < 0.2), and negative zeta potential (−20.5 mV). Our results indicated that the introduction of PF-127 strengthened the mucus-penetrating property of NPs. In vitro studies suggested that NPs with PF-127 enhanced the suppression of the secretion of proinflammatory cytokine TNF-α and reactive oxygen species (ROS) from RAW 264.7 macrophages under lipopolysaccharide stimulation in comparison with other counterparts. According to the evaluation of macro symptoms and main inflammatory cytokines, we further report preferable therapeutic outcomes achieved by PF-127 functionalized-NP-treated dextran sulphate sodium (DSS) groups in the colitis model compared with blank silk fibroin NPs and RSV-loaded NPs without the functionalization of PF-127. Taken together, this work suggests that the fabricated PF-127 NPs via the oral route are promising and useful RSV-loaded nanocarriers for UC treatment.

Folic acid-targeted pluronic F127 micelles improve oxidative stress and inhibit fibrosis for increasing AKI efficacy.

The oxidative stress and activation of the fibrosis pathway are essential pathological mechanisms of acute kidney injury (AKI). In this article, we designed a drug delivery system that could effectively improve oxidative stress and relieve fibrosis by the combination of precise targeting, solubilization, and reducing the toxicity of nano-transport system to strengthen the efficacy of AKI. Folic acid (FA) was used as the targeting molecule, and curcumin (Cur) and resveratrol (Res), which are Chinese medicine monomers with anti-inflammatory and antioxidant effects, were used as model drugs. Here, the targeting nanosystem (Cur/Res@FA-F127/TPGS) co-loaded with Cur and Res was successfully synthesized. Finally, the comprehensive therapeutic effect of the nanosystem was evaluated through the targeted and pharmacodynamic researches on the AKI models induced by cisplatin (CDDP) in vitro and in vivo. The studies in vitro proved that the nanosystem could not only specifically target HK-2 cells and promote the effective accumulation of Cur and Res in the kidney, but also effectively improve oxidative stress by eliminating reactive oxygen species (ROS), stabilizing mitochondrial membrane potential (MMP), and reducing the expression of apoptosis-related proteins. The studies in vivo showed that the nanosystem could effectively play the role of anti-oxidation, anti-inflammatory and alleviate fibrosis to reduce the apoptosis and necrosis of renal tubular cells. The nanosystem could coordinately repair damaged HK-2 cells by improving oxidative stress, inhibiting inflammation and tissue fibrosis, which provided a new idea for the treatment of AKI.

Poloxamer 188 - quercetin formulations amplify in vitro ganciclovir antiviral activity against cytomegalovirus.

Treatment of human cytomegalovirus (CMV) infection requires long-term administration of nucleoside analog antivirals such as ganciclovir (GCV), a therapy frequently limited by GCV-induced toxicity. Here, combining GCV treatment with two bioactive excipients, poloxamer 188 and quercetin, was investigated in vitro to reduce GCV dosage. Quercetin is a natural flavonoid exhibiting antiviral activity against CMV by a mechanism distinct from GCV, but is poorly soluble, limiting its use as a therapeutic. To overcome this challenge, quercetin was co-formulated with poloxamer 188 (P188, Pluronic ® F68). Quercetin-P188 (QP188) formulations yielded only modest CMV viral inhibition, with a selectivity index of 11.4, contrasted with a GCV selectivity index of 95. More significantly, when coadministered with GCV, QP188 exhibited an additive or synergistic interaction in subtherapeutic ranges of GCV. Fluorescence microscopy revealed QP188 accumulation in fibroblast mitochondria, suggesting that the excipient may modulate mitochondrial processes relevant to CMV infection. GCV antiviral therapy augmented with poloxamer-solubilized quercetin may be a viable approach to maintain CMV inhibition while lowering GCV doses, translating to reduced associated toxicity.

Novel Thermosensitive Hydrogel Promotes Spinal Cord Repair by Regulating Mitochondrial Function.

The repair of spinal cord injury (SCI) is still a tough clinical challenge and needs innovative therapies. Mitochondrial function is significantly compromised after SCI and has emerged as an important factor causing neuronal apoptosis and hindering functional recovery. In this study, umbilical cord mesenchymal stem cells (UCMSC), which are promising seed cells for nerve regeneration, and basic fibroblast growth factor (bFGF) that have been demonstrated to have a variety of effects on neural regeneration were jointly immobilized in extracellular matrix (ECM) and heparin-poloxamer (HP) to create a polymer bioactive system that brings more hope and possibility for the treatment of SCI. Our results in vitro and in vivo showed that the UCMSC-bFGF-ECM-HP thermosensitive hydrogel has good therapeutic effects, mainly in reducing apoptosis and improving the mitochondrial function. It showed promising utility for the functional recovery of impaired mitochondrial function by promoting mitochondrial fusion, reducing pathological mitochondrial fragmentation, increasing mitochondrial energy supply, and improving the metabolism of MDA, LDH, and ROS. In addition, we uncovered a distinct molecular mechanism underlying the protective effects associated with activating p21-activated kinase 1 (PAK1) and mitochondrial sirtuin 4 (SIRT4) by the UCMSC-bFGF-ECM-HP hydrogel. The expansion of new insights into the molecular relationships between PAK1 and SIRT4, which links the mitochondrial function in SCI, can lay the foundation for future applications and help to provide promising interventions of stem-cell-based biological scaffold therapies and potential therapeutic targets for the clinical formulation of SCI treatment strategies.

Glycosaminoglycan-based injectable hydrogels with multi-functions in the alleviation of osteoarthritis.

Osteoarthritis (OA), as an "undead cancer", causes a serious burden for both individuals and society. In this study, a glycosaminoglycan-based injectable hydrogel was prepared with hyaluronic acid (HA), chondroitin sulfate E disaccharide (ΔUA-diSE) and thermosensitive Pluronic F127 (PF127) to provide a new strategy for OA alleviation. Both in vitro and in vivo biological evaluations were introduced to investigate the slow-release capacity, related mechanisms, and effectiveness of PF-HA-diSE on OA. The results demonstrated that PF-HA-diSE could alleviate OA effectively by regulating the complement system, especially the formation of C5b-9, and its downstream signals. Interestingly, we also found that PF127 was not only a drug carrier, but may have the potential on inhibiting C5b-9 formation. Altogether, these findings provided a more effective local drug delivery system for glycosaminoglycans in better treatment of OA and related diseases.

Development and evaluation of PLA based hybrid block copolymeric nanoparticles for systemic delivery of pirarubicin as an anti-cancer agent.

Pirarubicin (PIRA) is a semi-synthetic anthracycline derivative that is reported to have lesser toxicity and better clinical outcomes as compared to its parental form doxorubicin (DOX). However, long term use of PIRA causes bone marrow suppression and severe cardiotoxicity to the recipients. Herein, we have developed a biodegradable polymeric nano platform consisting of amphiphilic di-block copolymer methoxy polyethylene glycol-polylactic acid and a hydrophobic penta-block copolymer polylactic acid-pluronic L-61-polylactic acid as a hybrid system to prepare PIRA (& DOX) encapsulated nanoparticles (NPs) with an aim to reduce its off targeted toxicity and enhance therapeutic efficacy for cancer therapy. Prepared PIRA/DOX NPs showed uniform particle size distribution, high encapsulation efficiency and sustained drug release profile. Cytotoxicity evaluation of PIRA NPs against TNBC cells and mammospheres showed its superior anti-cancer activity over DOX NPs. Anti-cancer efficacy of PIRA/DOX NPs was found significantly enhanced in presence of penta-block copolymer which confirmed chemo-sensitising ability of pluronic L-61. Most importantly, encapsulation of PIRA/DOX in the NPs reduced their off targeted toxicity and increased the maximum tolerated dose in BALB/c mice. Moreover, treatment of EAC tumor harbouring mice with PIRA NPs resulted in higher tumor regression as compared with the groups treated with free PIRA, free DOX or DOX NPs. Altogether, the results conclude that prepared PIRA NPs exhibits an excellent anti-cancer therapeutic efficacy and has a strong potential for cancer therapy.