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  • McLean Grimes posted an update 2 days, 8 hours ago

    Additionally, we demonstrate that TQ can inhibit the growth of xenografts and restrict the formation of tumor metastatic foci in the lung. Taken together, our findings confirm the antimetastatic effect of TQ in bladder cancer cells for the first time and also provide new evidence for the development of TQ as a novel treatment for metastatic bladder cancer. The therapeutic efficacy of orally administered drugs is often restricted by their inherent limited oral bioavailability. Low water solubility, limited permeability through the intestinal barrier, instability in harsh environment of the gastrointestinal (GI) tract and being substrate of the efflux pumps and the cytochrome P450 (CYP) can impair oral drug bioavailability resulting in erratic and variable plasma drug profile. As more drugs with low membrane permeability are developed, new interest is growing to enhance their intestinal permeability and bioavailability. A wide variety of nanosystems have been developed to improve drug transport and absorption. Sufficient evidence exists to suggest that nanoparticles are able to increase the transepithelial transport of drug molecules. However, key questions remained unanswered. What types of nanoparticles are more efficient? What are preclinical (or clinical) achievements of each type of nanoformulation in terms of pharmacokinetic (PK) parameters? Addressing this issue in this paper, we have reviewed the current literature regarding permeability enhancement, permeability assessment methods and changes in PK parameters following administration of various nanoformulations. Although permeability enhancement by various nanoformulations holds great promise for oral drug delivery, many challenges still need to be addressed before development of more clinically successful nanoproducts. We have previously reported the synthesis of a poly(ethylene glycol)-haloperidol (PEG-haloperidol) conjugate that retained affinity for its target D2 receptor and was stable in simulated physiological conditions. We hypothesised that this polymer-drug conjugate would localise haloperidol’s activity either centrally or peripherally, dependent on the location of administration, due to the polymer preventing penetration through the blood-brain barrier (BBB). Herein, we validate this hypothesis using in vitro and in vivo studies. We first demonstrate, via a [35S]GTPγS-binding assay, that drug activity is retained after conjugation to the polymer, supportive of retention of effective therapeutic ability. Specifically, the PEG-haloperidol conjugate (at 10 and 100 nM) was able to significantly inhibit dopamine-induced G-protein activation via D2 receptors, albeit with a loss of potency compared to the free haloperidol (~18-fold at 10 nM). This loss of potency was further probed and rationalised using molecular docking experiments, which indicated that conjugated haloperidol can still bind to the D2 receptors, albeit with a flipped orientation in the biding pocket within the receptor, which may explain the reduced activity. Finally, rat catalepsy studies confirmed the restricted permeation of the conjugate through the BBB in vivo. Rats treated intravenously with free haloperidol became cataleptic, whereas normal behaviour was observed in rats that received the PEG-haloperidol conjugate, suggesting that conjugation can effectively prevent unwanted central effects. Taken together these results demonstrate that conjugating small molecules to polymers is effective at prohibiting penetration of the drug through the BBB and is a valid targeting strategy for drugs to facilitate peripheral (or central) effects without inducing side effects in other compartments. V.Pancreatic ductal adenocarcinoma (PDAC) is rich in cancer-associated fibroblasts (CAFs), which participate in the formation of tumor stroma. However, the dense tumor stroma of PDAC presents major barriers to drug delivery, resulting in an obstacle for PDAC therapy. Considering the special tumor microenvironment of PDAC, we constructed a novel nanoparticle which is responsive to the membrane biomarker FAP-α on CAFs and near-infrared (NIR) laser irradiation. Small sized albumin nanoparticle of paclitaxel (HSA-PTX) with strong tumor-penetration ability was encapsulated into the CAP-(a FAP-α responsive cleavable amphiphilic peptide) modified thermosensitive liposomes (CAP-TSL). Moreover, IR-780, a photothermal agent, was incorporated into CAP-TSL to afford CAP-ITSL. The designed HSA-PTX@CAP-ITSL increased the drug retention of HSA-PTX in solid tumor and HSA-PTX was released via FAP-α (specifically expresses on CAFs) triggered. Under sequential stimulation of NIR laser irradiation, IR-780 produced hyperthermia to kill tumor cells and expand the tumor interstitial space at the same time, which further promoted the release of small sized HSA-PTX in deep tumor regions. Consequently, the excellent antitumor efficacy of HSA-PTX@CAP-ITSL was demonstrated in Pan 02 subcutaneous and orthotopic tumor mouse models. Therefore, HSA-PTX@CAP-ITSL well combined chemotherapy with photothermal therapy, providing a promising drug delivery strategy for PDAC treatment. Biodegradable microparticles (MPs) as vaccine adjuvants have sparked the passion of researchers in recent decades. However, it is still a huge challenge to develop an efficient vaccine delivery system to reverse chronic hepatitis B (CHB). Doramapimod in vitro Herein, we integrated a physiochemical merit and an immunopotentiator property in poly (lactic acid) (PLA) MPs and verified the therapeutic effect on CHB model mice. We prepared uniform MPs with insertion of cationic lipid didodecyldimethylammonium bromide (DDAB), which endowed a physiochemical merit for MPs. Such a DDAB-PLA (DP) group raised the recruitment of immune cells to the injection site along with the secretion of chemokines and pro-inflammatory cytokines, promoting the activation of antigen-presenting cells (APCs). Further combination of stimulator of interferon genes (STING) agonist 5,6-dimethylxanthenone-4-acetic acid (DMXAA) (DP-D) elevated 5.8-fold higher interferon regulatory factor 7 (IRF-7) expression compared to that for DP group. The DP group showed preferred lysosome escape advantage, which was in line with the DMXAA release behavior and the intracellular target of DMXAA.

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