An injectable signal-amplifying device elicits a specific immune response against malignant glioblastoma.

Despite exciting achievements with some malignancies, immunotherapy for hypoimmunogenic cancers, especially glioblastoma (GBM), remains a formidable clinical challenge. Poor immunogenicity and deficient immune infiltrates are two major limitations to an effective cancer-specific immune response. Herein, we propose that an injectable signal-amplifying nanocomposite/hydrogel system consisting of granulocyte-macrophage colony-stimulating factor and imiquimod-loaded antigen-capturing nanoparticles can simultaneously amplify the chemotactic signal of antigen-presenting cells and the "danger" signal of GBM. We demonstrated the feasibility of this strategy in two scenarios of GBM. In the first scenario, we showed that this simultaneous amplification system, in conjunction with local chemotherapy, enhanced both the immunogenicity and immune infiltrates in a recurrent GBM model; thus, ultimately making a cold GBM hot and suppressing postoperative relapse. Encouraged by excellent efficacy, we further exploited this signal-amplifying system to improve the efficiency of vaccine lysate in the treatment of refractory multiple GBM, a disease with limited clinical treatment options. In general, this biomaterial-based immune signal amplification system represents a unique approach to restore GBM-specific immunity and may provide a beneficial preliminary treatment for other clinically refractory malignancies.

Anti-glioma effect of ginseng-derived exosomes-like nanoparticles by active blood-brain-barrier penetration and tumor microenvironment modulation.

Inhibition of tumor growth and normalization of immune responses in the tumor microenvironment (TME) are critical issues for improving cancer therapy. However, in the treatment of glioma, effective nanomedicine has limited access to the brain because of the blood-brain barrier (BBB). Previously, we demonstrated nano-sized ginseng-derived exosome-like nanoparticles (GENs) consisting of phospholipids including various bioactive components, and evaluated anti-tumor immune responses in T cells and Tregs to inhibit tumor progression. It was found that the enhanced targeting ability of GENs to the BBB and glioma induced a significant therapeutic effect and exhibited strong efficacy in recruiting M1 macrophage expression in the TME. GENs were demonstrated to be successful candidates in glioma therapeutics both in vitro and in vivo, suggesting excellent potential for inhibiting glioma progression and regulating tumor-associated macrophages (TAMs).

Human-murine chimeric autoantibodies with high affinity and specificity for systemic sclerosis.

Scleroderma 70 (Scl-70) is commonly used in the clinic for aiding systemic sclerosis (SSc) diagnosis due to its recognition as autoantibodies in the serum of SSc patients. However, obtaining sera positive for anti-Scl-70 antibody can be challenging; therefore, there is an urgent need to develop a specific, sensitive, and easily available reference for SSc diagnosis. In this study, murine-sourced scFv library were screened by phage display technology against human Scl-70, and the scFvs with high affinity were constructed into humanized antibodies for clinical application. Finally, ten high-affinity scFv fragments were obtained. Three fragments (2A, 2AB, and 2HD) were select for humanization. The physicochemical properties of the amino acid sequence, three-dimensional structural basis, and electrostatic potential distribution of the protein surface of different scFv fragments revealed differences in the electrostatic potential of their CDR regions determined their affinity for Scl-70 and expression. Notably, the specificity test showed the half-maximal effective concentration values of the three humanized antibodies were lower than that of positive patient serum. Moreover, these humanized antibodies showed high specificity for Scl-70 in diagnostic immunoassays for ANA. Among these three antibodies, 2A exhibited most positive electrostatic potential on the surface of the CDRs and highest affinity and specificity for Scl-70 but with least expression level; thus, it may provide new foundations for developing enhanced diagnostic strategies for SSc.

Advances in Small Molecules of Flavonoids for the Regulation of Gluconeogenesis.

Hyperglycemia resulting from over-gluconeogenesis is a prominent feature of type 2 diabetes mellitus (T2DM). Therefore, it is very important to reduce glucose output, especially liver glucose output, and maintain blood glucose homeostasis in the treatment of T2DM. It has been found that small molecules of natural flavonoids are able to act on various targets in the gluconeogenic pathways, interfering with rate-limiting enzyme activity or regulating the cascade of hormonal signaling and affecting all levels of transcription factors by limiting the transport of non-sugar substrates. As a result, gluconeogenesis is inhibited. Literature indicated that gluconeogenesis regulated by flavonoids could be divided into two pathways, namely the pre-translational pathway and the pro-translational pathway. The pre-translational pathway mainly interferes with the signaling pathway and transcription factors in gluconeogenesis and inhibits RNA transcription and the expression of gluconeogenic genes, while the post-translational pathway mainly regulates the transport of nonglucose substrates and directly inhibits four rate-limiting enzymes. This review describes the effects of small flavonoid molecules on different targets and signaling pathways during gluconeogenesis, as well as relevant validation methods, in the hope of providing references for similar studies and promoting the development of anti-diabetic drugs.

Curcumin combining temozolomide formed localized nanogel for inhibition of postsurgical chemoresistant glioblastoma.

Aim: To investigate the use of nanoparticle (NP)-encapsulated injectable thermosensitive hydrogel-formed nanogel for inhibition of postsurgical residual temozolomide (TMZ)-resistant glioblastoma (GBM) recurrence. Materials & methods: Curcumin (Cur) was coloaded with TMZ into PEG-PLGA NPs, then NPs were further encapsulated into a thermosensitive hydrogel to form a nanogel, which was injected into the resection cavity of the GBM postsurgery. Results: The prepared nanogel displayed excellent drug-loading capacity and long-term drug release. Estimated survival characteristics demonstrated that the nanogel could play a significant role in TMZ-resistant tumor inhibition with low drug-induced toxicity. The originally designed ratio of Cur/TMZ was sustained, making it an effective therapeutic outcome. Conclusion: Cur-combined TMZ-formed nanogels can be a promising candidate for the local inhibition of GBM recurrence.

In this study, the animal model used was rats suffering residual brain tumor after resection. The selected drugs were temozolomide, a first-line chemotherapeutic drug for the clinical treatment of glioma, and curcumin, an extract from the ginger plant. With the use of temozolomide, brain glioma cells gradually develop resistance, resulting in poor efficacy of temozolomide. Therefore, the purpose of this study was to construct a drug-delivery system for temozolomide-resistant brain glioma residual tumor after surgery, namely, a temperature-sensitive gel containing drug-carrying nanopreparations ­ the so-called nanogels. This drug-delivery system can directly deliver drugs to residual tumor cells in situ after surgery. In situ drug-delivery systems can reduce the dose of drugs consumed and increase their potency compared to oral or intravenous administration.

Nanobiotechnology-based treatment strategies for malignant relapsed glioma.

Gliomas are the most aggressive and lethal tumors of the central nervous system, for which few therapeutic options exist. Surgical resection is the primary treatment for most gliomas; however, tumor recurrence is nearly inevitable. Emerging nanobiotechnology-based strategies have shown great prospects for early glioma diagnosis, physiological barrier traversing, postoperative regrowth suppression, and microenvironment remodeling. Herein, we focus on the postoperative scenario and summarize the key properties of the glioma microenvironment, especially its immune peculiarities. We elucidate the challenges of managing recurrent glioma. We also discuss the potential of nanobiotechnology in addressing the therapeutic challenges of recurrent glioma, including optimizing the design of drug delivery systems, enhancing intracranial accumulation, and restoring the anti-glioma immune response. The development of these technologies offers new opportunities for accelerating the drug development process and treating recurrent glioma.

Advances in natural small molecules on pretranslational regulation of gluconeogenesis.

Different tissues and organs coordinate to keep glucose levels at homeostasis. However, excessive gluconeogenesis in patients with type 2 diabetes mellitus increases blood glucose and causes dysregulation of homeostasis, which easily induces various diseases. Therefore, inhibiting excessive gluconeogenesis is a potential direction to regulate the disorder of blood glucose homeostasis and treat diabetes. The process of gluconeogenesis can be pretranslationally or posttranslationally regulated, and some natural small molecules can be involved in the pretranslational phase of gluconeogenesis, regulating glucose homeostasis by inhibiting gene expression, interfering with RNA transcription, and antagonizing related proteins. This paper will classify and review the natural small molecules with pretranslational regulation of gluconeogenesis according to the action sites and signaling pathways.

Dual-sensitive drug-loaded hydrogel system for local inhibition of post-surgical glioma recurrence.

Local treatment after resection to inhibit glioma recurrence is thought to able to meet the real medical needs. However, the only clinically approved local glioma treatment-wafer containing bis(2-chloroethyl) nitrosourea (BCNU) showed very limited effects. Herein, in order to inhibit tumor recurrence with prolonged and synergistic therapeutic effect of drugs after tumor resection, an in situ dual-sensitive hydrogel drug delivery system loaded with two synergistic chemo-drugs BCNU and temozolomide (TMZ) was developed. The thermosensitive hydrogel was loaded with reactive oxygen species (ROS)-sensitive poly (lactic-co-glycolic) acid nanoparticles (NPs) encapsulating both BCNU and TMZ and also free BCNU and TMZ. The in vitro synergistic effect of BCNU and TMZ and in vivo presence of ROS at the residual tumor site were confirmed. The prepared ROS-sensitive NPs and thermosensitive hydrogel, as well as the long-term release behavior of drugs and NPs, were fully characterized both in vitro and in vivo. After >90% glioblastoma resection, the dual-sensitive hydrogel drug delivery system was injected into the resection cavity. The median survival time of the experimental group reached 65 days which was twice as long as the Resection only group, implying that this in situ drug delivery system effectively inhibited tumor recurrence. Overall, this study provides new ideas and strategies for the inhibition of postoperative glioma recurrence.

Cell-Permeable, MMP-2 Activatable, Nickel Ferrite and His-Tagged Fusion Protein Self-Assembled Fluorescent Nanoprobe for Tumor Magnetic-Targeting and Imaging.

Matrix metalloproteinases (MMPs) activatable imaging probe has been explored for tumor detection. However, activation of the probe is mainly done in the extracellular space without intracellular uptake of the probe for more sensitivity. Although cell-penetrating peptides (CPPs) have been demonstrated to enable intracellular delivery of the imaging probe, they nevertheless encounter off-target delivery of the cargos to normal tissues. Herein, we have developed a dual MMP-2-activatable and tumor cell-permeable magnetic nanoprobe to simultaneously achieve selective and intracellular tumor imaging. This novel imaging probe was constructed by self-assembling a hexahistidine-tagged (His-tagged) fluorescent fusion protein chimera and nickel ferrite nanoparticles via a chelation mechanism. The His-tagged fluorescent protein chimera consisted of a red fluorescent protein mCherry that acted as the fluorophore, the low-molecular-weight protamine peptide as the CPP, and the MMP-2 cleavage sequence fused with the hexahistidine tag, whereas the nickel ferrite nanoparticles functioned as the His-tagged protein binder and also the fluorescent quencher. Both in vitro and in vivo results revealed that this imaging probe would not only remain nonpermeable to normal tissues, thereby offsetting the nonselective cellular uptake, but was also suppressed of fluorescent signals during magnetic tumor-targeting in the circulation, primarily because of the masking of the CPP activity and quenching of the fluorophore by the associated NiFe2O4 nanoparticles. However, these properties were recovered or "turned on" by the action of tumor-associated MMP-2 stimuli, leading to cell penetration of the nanoprobes as well as fluorescence restoration and visualization within the tumor cells. In this regard, the presented tumor-activatable and cell-permeable system deems to be an appealing platform to achieve selective tumor imaging and intracellular protein delivery. Its impact is therefore significant, far-reaching, and wide-spread.

Curcumin/sunitinib co-loaded BSA-stabilized SPIOs for synergistic combination therapy for breast cancer.

Coating supermagnetic iron oxide nanoparticles (SPIOs) with albumin would not only improve their in vivo stability but also improve their drug loading capacity, but current methods are either inefficient or time consuming. Herein, a single step synthesis of bovine serum albumin (BSA)-stabilized SPIOs with high dispersity and stability via a modified co-precipitation method is reported. The benefits of albumin for coating of SPIOs, i.e. its long circulation life, low immunogenicity and drug binding ability to specific binding domains, were all retained in our mildly modified BSA. The BSA-SPIOs thus prepared displayed an excellent T2 contrast enhancing effect and drug loading capacity. Two cytotoxic drugs curcumin and sunitinib, where the former is a drug-resistance depressor and the latter is a tyrosine kinase inhibitor, were further co-loaded into the BSA-SPIOs (denoted SPIO-SC) to achieve combined synergistic therapy. SPIO-SC formulations displayed the most significant tumor inhibition yet least drug-induced toxicity both in vitro and in vivo when compared with free drug formulations. Through in vivo pharmacokinetic analysis, it was demonstrated that SPIO-SC most efficiently delivered the encapsulated drugs to the tumor site, and at the same time maintained the originally designed, optimal ratios of curcumin to sunitinib concentrations at the tumor target and yielded the most optimal synergistic effect and, subsequently, the more effective therapeutic outcomes. The prepared BSA-SPIOs are an extremely promising candidate for both MR imaging and drug delivery as a healthcare material.

CPP-Assisted Intracellular Drug Delivery, What Is Next?

For the past 20 years, we have witnessed an unprecedented and, indeed, rather miraculous event of how cell-penetrating peptides (CPPs), the naturally originated penetrating enhancers, help overcome the membrane barrier that has hindered the access of bio-macromolecular compounds such as genes and proteins into cells, thereby denying their clinical potential to become potent anti-cancer drugs. By taking the advantage of the unique cell-translocation property of these short peptides, various payloads of proteins, nucleic acids, or even nanoparticle-based carriers were delivered into all cell types with unparalleled efficiency. However, non-specific CPP-mediated cell penetration into normal tissues can lead to widespread organ distribution of the payloads, thereby reducing the therapeutic efficacy of the drug and at the same time increasing the drug-induced toxic effects. In view of these challenges, we present herein a review of the new designs of CPP-linked vehicles and strategies to achieve highly effective yet less toxic chemotherapy in combating tumor oncology.

Enhancing insulin oral absorption by using mucoadhesive nanoparticles loaded with LMWP-linked insulin conjugates.

Although significant progress has been achieved, effective oral delivery of protein drugs such as insulin by nanoparticle-based carrier systems still faces certain formidable challenges. Considerable amount of protein drug is released from the nanoparticles (NPs) in the gastrointestinal (GI) tract. Because of their low permeability through the intestinal mucosa, the released protein would be soon degraded by the large amount of proteases in the GI tract. Herein, we report an oral insulin delivery system that can overcome the above-mentioned problems by mucoadhesive NPs (MNPs) loaded with cell penetrating peptide-linked insulin conjugates. On one hand, after conjugation with low molecular weight protamine (LMWP), a cell penetrating peptide (CPP), insulin showed greatly improved permeability through intestinal mucus layer and epithelia. On the other hand, the mucoadhesive N-trimethyl chitosan chloride-coated PLGA nanoparticles (MNPs) that were loaded with conjugates enhanced the retention in the intestinal mucus layer. By adopting this delivery strategy, the LMWP-insulin conjugates released from the MNPs could be deprived from enzymatic degradation, due to the short distance in reaching the epithelia and the high permeation of the conjugates through epithelia. The oral delivery system of insulin designed by us showed a long-lasting hypoglycemia effect with a faster onset in diabetic rats. The pharmacological availability of orally delivered conjugates-loaded MNPs was 17.98±5.61% relative to subcutaneously injected insulin solution, with a 2-fold higher improvement over that by MNPs loaded with native insulin. Our results suggested that conjugation with CPP followed by encapsulation in MNPs provides an effective strategy for oral delivery of macromolecular therapeutics.

Enzyme-triggered, cell penetrating peptide-mediated delivery of anti-tumor agents.

Conventional chemotherapy has little or no specificity for cancer cells, normally resulting in low drug accumulation at the tumor region (inefficacy) and drug-induced severe side effects (toxicity). Nowadays, new strategies have been developed to improve both the targeting ability and cellular drug uptake using active targeting ligands and drug internalization agents, which could recognize and interact with specific receptors overexpressed on tumor cells and then trigger a drug internalization process by transporting the cargos into cells. Among those strategies, enzyme-triggered cell penetrating peptide (CPP)-mediated systems seem to be a feasible approach. The expression level of specific enzymes like proteases, esterases or glycosidases is often higher in tumor cells than in normal tissues, and such concentration gradients can be exploited as a tool for targeted cancer therapy. CPPs are known to be effective in promoting membrane transportation of the drug cargos, rendering a deeper tumor permeation that could further enhance the therapeutic efficacy of the delivered drug. An enzyme-triggered, CPP-mediated system would combine these advantages to yield a system with the enhanced tumor targeting ability and internalization efficiency and so far many systems have been successfully exploited and applied to cancer therapy. In this review, typical enzymes applied in cancer theranostic systems were firstly reviewed, followed by analyzing pros and cons of cell penetrating peptides. Most importantly, different types of applications of enzyme-triggered CPP-mediated systems in tumor imaging were illustrated. Finally, the drug loaded applications, i.e. enzyme-triggered CPP-mediated systems in drug delivery were reviewed.