Polymeric-based particulate systems for delivery of therapeutic proteins

Engineered therapeutic proteins for sustained-release drug delivery systems

Proteins play a vital role in diverse biological processes in the human body, and protein therapeutics have been applied to treat different diseases such as cancers, genetic disorders, autoimmunity, and inflammation. Protein therapeutics have demonstrated their advantages, such as specific pharmaceutical effects, low toxicity, and strong solubility. However, several disadvantages arise in clinical applications, including short half-life, immunogenicity, and low permeation, leading to reduced drug effectiveness. The structure of protein therapeutics can be modified to increase molecular size, leading to prolonged stability and increased plasma half-life. Notably, the controlled-release delivery systems for the sustained release of protein drugs and preserving the stability of cargo proteins are envisioned as a potential approach to overcome these challenges. In this review, we summarize recent research progress related to structural modifications (PEGylation, glycosylation, poly amino acid modification, and molecular biology-based strategies) and promising long-term delivery systems, such as polymer-based systems (injectable gel/implants, microparticles, nanoparticles, micro/nanogels, functional polymers), lipid-based systems (liposomes, solid lipid nanoparticles, nanostructured lipid carriers), and inorganic nanoparticles exploited for protein therapeutics. STATEMENT OF SIGNIFICANCE: In this review, we highlight recent advances concerning modifying proteins directly to enhance their stability and functionality and discuss state-of-the-art methods for the delivery and controlled long-term release of active protein therapeutics to their target site. In terms of drug modifications, four widely used strategies, including PEGylation, poly amino acid modification, glycosylation, and genetic, are discussed. As for drug delivery systems, we emphasize recent progress relating to polymer-based systems, lipid-based systems developed, and inorganic nanoparticles for protein sustained-release delivery. This review points out the areas requiring focused research attention before the full potential of protein therapeutics for human health and disease can be realized.

Long noncoding RNA Regulating ImMune Escape regulates mixed lineage leukaemia protein-1-H3K4me3-mediated immune escape in oesophageal squamous cell carcinoma

BACKGROUND

Predictive biomarkers for oesophageal squamous cell carcinoma (ESCC) immunotherapy are lacking, and immunotherapy resistance remains to be addressed. The role of long noncoding RNA (lncRNA) in ESCC immune escape and immunotherapy resistance remains to be elucidated.

METHODS

The tumour-associated macrophage-upregulated lncRNAs and the exosomal lncRNAs highly expressed in ESCC immunotherapy nonresponders were identified by lncRNA sequencing and polymerase chain reaction assays. CRISPR-Cas9 was used to explore the functional roles of the lncRNA. RNA pull-down, MS2-tagged RNA affinity purification (MS2-TRAP) and RNA-binding protein immunoprecipitation (RIP) were performed to identify lncRNA-associated proteins and related mechanisms. In vivo, the humanized PBMC (hu-PBMC) mouse model was established to assess the therapeutic responses of specific lncRNA inhibitors and their combination with programmed cell death protein 1 (PD-1) monoclonal antibody (mAb). Single-cell sequencing, flow cytometry, and multiplex fluorescent immunohistochemistry were used to analyze immune cells infiltrating the tumour microenvironment.

RESULTS

We identified a lncRNA that is involved in tumour immune evasion and immunotherapy resistance. High LINC02096 (RIME) expression in plasma exosomes correlates with a reduced response to PD-1 mAb treatment and poor prognosis. Mechanistically, RIME binds to mixed lineage leukaemia protein-1 (MLL1) and prevents ankyrin repeat and SOCS box containing 2 (ASB2)-mediated MLL1 ubiquitination, improving the stability of MLL1. RIME-MLL1 increases H3K4me3 levels in the promoter regions of programmed death-ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO-1), constitutively increasing the expression of PD-L1/IDO-1 in tumour cells and inhibiting CD8+ T cells infiltration and activation. RIME depletion in huPBMC-NOG mice significantly represses tumour development and improves the effectiveness of PD-1 mAb treatment by activating T-cell-mediated antitumour immunity.

CONCLUSIONS

This study reveals that the RIME-MLL1-H3K4me3 axis plays a critical role in tumour immunosuppression. Moreover, RIME appears to be a potential prognostic biomarker for immunotherapy and developing drugs that target RIME may be a new therapeutic strategy that overcomes immunotherapy resistance and benefits patients with ESCC.

Formulation and Evaluation of Chitosan-PLGA Biocomposite Scaffolds Incorporated with Quercetin Liposomes Made by QbD Approach for Improved Healing of Oral Lesions

The current research aims to develop and evaluate chitosan-PLGA biocomposite scaffolds in combination with quercetin liposomes to accomplish the desired impact in oral lesions where pharmacotherapeutic agent treatment through circulation could only reach the low content at the target. Optimization of quercetin-loaded liposomes was carried out using 32 factorial design. The preparation of porous scaffolds comprising produced quercetin-loaded liposomes by thin-film method was carried out in the current study using a unique strategy combining solvent casting and gas foaming procedures. The prepared scaffolds were tested for physicochemical properties, in vitro quercetin release study, ex vivo drug permeation and retention research using goat mucosa, antibacterial activity, and cell migration studies on fibroblast L929 cell lines. Improved cell growth and migration were seen in the order control < liposomes < proposed system. The proposed system has been examined for its biological and physicochemical features, and it has the potential to be utilized as an efficient therapy for oral lesions.

Enhancing the Effectiveness of Oligonucleotide Therapeutics Using Cell-Penetrating Peptide Conjugation, Chemical Modification, and Carrier-Based Delivery Strategies

Oligonucleotide-based therapies are a promising approach for treating a wide range of hard-to-treat diseases, particularly genetic and rare diseases. These therapies involve the use of short synthetic sequences of DNA or RNA that can modulate gene expression or inhibit proteins through various mechanisms. Despite the potential of these therapies, a significant barrier to their widespread use is the difficulty in ensuring their uptake by target cells/tissues. Strategies to overcome this challenge include cell-penetrating peptide conjugation, chemical modification, nanoparticle formulation, and the use of endogenous vesicles, spherical nucleic acids, and smart material-based delivery vehicles. This article provides an overview of these strategies and their potential for the efficient delivery of oligonucleotide drugs, as well as the safety and toxicity considerations, regulatory requirements, and challenges in translating these therapies from the laboratory to the clinic.

A perspective on oligonucleotide therapy: Approaches to patient customization

It is estimated that the human genome encodes 15% of proteins that are considered to be disease-modifying. Only 2% of these proteins possess a druggable site that the approved clinical candidates target. Due to this disparity, there is an immense need to develop therapeutics that may better mitigate the disease or disorders aroused by non-druggable and druggable proteins or enzymes. The recent surge in approved oligonucleotide therapeutics (OT) indicates the imminent potential of these therapies. Oligonucleotide-based therapeutics are of intermediate size with much-improved selectivity towards the target and fewer off-target effects than small molecules. The OTs include Antisense RNAs, MicroRNA (MIR), small interfering RNA (siRNA), and aptamers, which are currently being explored for their use in neurodegenerative disorders, cancer, and even orphan diseases. The present review is a congregated effort to present the past and present of OTs and the current efforts to make OTs for plausible future therapeutics. The review provides updated literature on the challenges and bottlenecks of OT and recent advancements in OT drug delivery. Further, this review deliberates on a newly emerging approach to personalized treatment for patients with rare and fatal diseases with OT.

Methods of Encapsulation of Biomacromolecules and Living Cells. Prospects of Using Metal–Organic Frameworks

The review discusses different methods of encapsulation and biomineralization of macromolecules and living cells. Main advantages and disadvantages of most commonly used carriers, matrices, and materials for immobilization of proteins, enzymes, nucleic acids, and living cells are briefly surveyed. Examples of delivery vehicles for multifunctional encapsulation of protein-like substances are presented. Particular attention is paid to prospects of using metal–organic frameworks in medicine and biotechnology.

Drug Delivery Systems on Leprosy Therapy: Moving Towards Eradication?

Leprosy disease remains an important public health issue as it is still endemic in several countries. Mycobacterium leprae, the causative agent of leprosy, presents tropism for cells of the reticuloendothelial and peripheral nervous system. Current multidrug therapy consists of clofazimine, dapsone and rifampicin. Despite significant improvements in leprosy treatment, in most programs, successful completion of the therapy is still sub-optimal. Drug resistance has emerged in some countries. This review discusses the status of leprosy disease worldwide, providing information regarding infectious agents, clinical manifestations, diagnosis, actual treatment and future perspectives and strategies on targets for an efficient targeted delivery therapy.

A pH-activated charge convertible quantum dot as a novel nanocarrier for targeted protein delivery and real-time cancer cell imaging

The rapid developments of nanocarriers based on quantum dots (QDs) have been confirmed to show substantial promise for drug delivery and bioimaging. However, optimal QDs-based nanocarriers still need to have their controlled behavior in vitro and in vivo and decrease heavy metal-associated cytotoxicity. Herein, a pH-activated charge convertible QD-based nanocarrier was fabricated by capping multifunctional polypeptide ligands (mPEG-block-poly(ethylenediamine-dihydrolipoic acid-2,3-dimethylmaleic anhydride)-L-glutamate, PEG-P(ED-DLA-DMA)LG) onto the surface of core/multishell CdSe@ZnS/ZnS QD by means of a ligand exchange strategy, followed by uploading of cytochrome C (CC) (CC-loaded QD-PEG-P(ED-DLA-DMA)LG) via electrostatic interactions, in which QDs that were water-soluble and protein-loading were perfectly integrated. That is, the CC-loaded QD-PEG-P(ED-DLA-DMA)LG inherited excellent fluorescence properties from CdSe@ZnS/ZnS QD for real-time imaging, as well as tumor-microenvironment sensitivities from PEG-P(ED-DLA-DMA)LG for enhanced cellular uptake and CC release. Experimental results verified that the QD-PEG-P(ED-DLA-DMA)LG showed enhanced internalization, rapid endo/lysosomal escape, and supplied legible real-time imaging for lung carcinoma cells. Furthermore, pH-triggered charge-convertible ability enabled the QD-PEG-P(ED-DLA-DMA)LG-CC to effectively kill cancer cells better than did the control groups. Hence, constructing smart nanocomposites by facile ligand-exchange strategy is beneficial to QD-based nanocarrier for tumor-targeting cancer therapy.

Redox-Active Polymers Connecting Living Microbial Cells to an Extracellular Electrical Circuit

Microbial electrochemical systems in which metabolic electrons in living microbes have been extracted to or injected from an extracellular electrical circuit have attracted considerable attention as environmentally-friendly energy conversion systems. Since general microbes cannot exchange electrons with extracellular solids, electron mediators are needed to connect living cells to an extracellular electrode. Although hydrophobic small molecules that can penetrate cell membranes are commonly used as electron mediators, they cannot be dissolved at high concentrations in aqueous media. The use of hydrophobic mediators in combination with small hydrophilic redox molecules can substantially increase the efficiency of the extracellular electron transfer process, but this method has side effects, in some cases, such as cytotoxicity and environmental pollution. In this Review, recently-developed redox-active polymers are highlighted as a new type of electron mediator that has less cytotoxicity than many conventional electron mediators. Owing to the design flexibility of polymer structures, important parameters that affect electron transport properties, such as redox potential, the balance of hydrophobicity and hydrophilicity, and electron conductivity, can be systematically regulated.

Delivery of genome editing tools: A promising strategy for HPV-related cervical malignancy therapy

INTRODUCTION

Persistent high-risk human papillomavirus infection is the main cause of various types of cancer especially cervical cancer. The E6 and E7 oncoproteins of HPV play critical roles in promoting carcinogenesis and cancer cell growth. As a result, E6 and E7 oncogenes are considered as promising therapeutic targets for cervical cancer. Recently, the development of genome-editing technologies including transcription activator-like effector nucleases (TALEN), meganucleases (MNs), zinc finger nucleases (ZFN), and more importantly clustered regularly interspaced short palindromic repeat-CRISPR-associated protein (CRISPR-Cas) has sparked a revolution in the cervical cancer-targeted therapy. However, due to immunogenicity, off-target effect, renal clearance, guide RNA (gRNA) nuclease degradation, and difficult direct transportation into the cytoplasm and nucleus, the safe and effective delivery is considered as the Achilles' heel of this robust strategy.

AREAS COVERED

In this review, we discuss cutting-edge available strategies for in vivo delivery of genome-editing technologies for HPV-induced cervical cancer therapy. Moreover, the combination of genome-editing tools and other therapies has been fully discussed.

EXPERT OPINION

The combination of nanoparticle-based delivery systems and genome-editing tools is a promising powerful strategy for cervical cancer therapy. The most significant limitations of this strategy that need to be focused on are low efficiency and off-target events.

Modelling protein therapeutic co-formulation and co-delivery with PLGA nanoparticles continuously manufactured by microfluidics

Formulating protein therapeutics into nanoparticles (NPs) of poly(lactic-co-glycolic acid) (PLGA) provides key features such as protection against clearance, sustained release and less side effects by possible attachment of targeting ligands.

Oral Pharmacokinetics of a Chitosan-Based Nano- Drug Delivery System of Interferon Alpha

Interferon alpha (IFNα) is a protein drug used to treat viral infections and cancer diseases. Due to its poor stability in the gastrointestinal tract, only parenteral administration ensures bioavailability, which is associated with severe side effects. We hypothesized that the nanoencapsulation of IFNα within nanoparticles of the mucoadhesive polysaccharide chitosan would improve the oral bioavailability of this drug. In this work, we produced IFNα-loaded chitosan nanoparticles by the ionotropic gelation method. Their hydrodynamic diameter, polydispersity index and concentration were characterized by dynamic light scattering and nanoparticle tracking analysis. After confirming their good cell compatibility in Caco-2 and WISH cells, the permeability of unmodified and poly(ethylene glycol) (PEG)-modified (PEGylated) nanoparticles was measured in monoculture (Caco-2) and co-culture (Caco-2/HT29-MTX) cell monolayers. Results indicated that the nanoparticles cross the intestinal epithelium mainly by the paracellular route. Finally, the study of the oral pharmacokinetics of nanoencapsulated IFNα in BalbC mice revealed two maxima and area-under-the-curve of 56.9 pg*h/mL.

Development of Antibacterial Nanocomposite: Whey Protein-Gelatin-Nanoclay Films with Orange Peel Extract and Tripolyphosphate as Potential Food Packaging

Antibacterial and biodegradable whey protein isolate (WPI-) gelatin nanocomposites were prepared using natural orange peel extract (OPE) in percentage of 7, 14, and 21% (v/v solution) and Cloisite 30B (5% w/w dry whey protein) made by a casting method. Mechanical, physical, and antibacterial properties of prepared films were measured as a function of OPE concentration. Higher concentrations of OPE led to higher antibacterial activity, tensile strength, and water solubility, but lower moisture content and transparency. The films microstructures were studied by field emission scanning electron microscopy (FESEM) and ATR-FTIR. Overall, the film containing 21%(v/v) OPE resulted in the best antibacterial, mechanical, and physical performance. Addition of tripolyphosphate (TPP) as a crosslinker to this sample led to the significant increase in transparency. Cloisite 30B, OPE, and TPP can therefore be used to improve the properties of WPI films as a promising natural food packaging.

Adhesive thermosensitive gels for local delivery of viral vectors

Local delivery of viral vectors can enhance the efficacy of therapies by selectively affecting necessary tissues and reducing the required vector dose. Pluronic F127 is a thermosensitive polymer that undergoes a solution-gelation (sol-gel) transition as temperature increases and can deliver vectors without damaging them. While pluronics can be spread over large areas, such as the surface of an organ, before gelation, they lack sufficient adhesivity to remain attached to some tissues, such as the surface of the heart or mucosal surfaces. Here, we utilized blends of pluronic F127 and polycarbophil (PCB), a mucoadhesive agent, to provide the necessary adhesivity for local delivery of viral vectors to the cardiac muscle. The effects of PCB concentration on adhesive properties, sol-gel temperature transition and cytocompatibility were evaluated. Rheological studies showed that PCB decreased the sol-gel transition temperature at concentrations >1% and increased the adhesive properties of the gel. Furthermore, these gels were able to deliver viral vectors and transduce cells in vitro and in vivo in a neonatal mouse apical resection model. These gels could be a useful platform for delivering viral vectors over the surface of organs where increased adhesivity is required.

Pharmacological effects of nanoencapsulation of human-based dosing of probucol on ratio of secondary to primary bile acids in gut, during induction and progression of type 1 diabetes

INTRODUCTION

The ratio of secondary to primary bile acids changes during Type 1 Diabetes (T1D) development and these effects might be ameliorated by using cholesterol lowering drugs or hydrophilic bile acids. Probucol is a cholesterol-lowering drug, while ursodeoxycholic acid is a hydrophilic bile acid. This study investigated whether nanoencapsulated probucol with ursodeoxycholic acid altered bile acid ratios and the development of diabetes.

METHODS

Balb/c mice were divided into three groups and gavaged daily with either free probucol, nanoencapsulated probucol or nanoencapsulated probucol with ursodeoxycholic acid for seven days. Alloxan was injected and once T1D was confirmed the mice continued to receive daily gavages until euthanasia. Blood, tissues, faeces and urine were collected for analysis of insulin and bile acids.

RESULTS AND CONCLUSIONS

Nanoencapsulated probucol-ursodeoxycholic acid resulted in significant levels of insulin in the blood, lower levels of secondary bile acids in liver and lower levels of primary bile acids in brain, while ratio of secondary to primary bile acids remains similar among all groups, except in the faeces. Findings suggests that nanoencapsulated probucol-ursodeoxycholic acid may exert a protective effect on pancreatic β-cells and reserve systemic insulin load via modulation of bile acid concentrations in the liver and brain.

Pluronic-Based Mixed Polymeric Micelles Enhance the Therapeutic Potential of Curcumin

Curcumin is a naturally occurring constituent of turmeric that is a good substitute for synthetic medicines for the treatment of different diseases, due to its comparatively safer profile. However, there are certain shortcomings that limit its use as an ideal therapeutic agent. In order to overcome these drawbacks, we prepared novel curcumin-loaded mixed polymeric micelles using different biocompatible polymers by the thin-film hydration method. We investigated the critical micelle concentration and temperature, drug loading and encapsulation efficiency, and minimum inhibitory concentration by spectrophotometry. Surface morphology, stability, particle size, drug-polymer interaction, and physical state of the prepared formulations were investigated using scanning electron microscopy, zeta potential, particle size analyzer, Fourier-transform infrared spectroscopy, and X-ray diffraction, respectively. The drug loading and entrapment efficiency were significantly increased (P < 0.01) when curcumin was encapsulated with pluronic-based mixed polymeric micelles as compared to that of pluronic-based micelles alone. In vitro studies exhibited that pluronic-based mixed polymeric micelles significantly increased anticancer (P < 0.01), antimicrobial (P < 0.001), antioxidant (P < 0.001), and α-amylase inhibitory (P < 0.001) activities when compared to pure curcumin and/or pluronic-based micelles alone. These findings suggest that the formation of mixed polymeric micelles increases the stability and solubility of curcumin.

Advance in oral delivery systems for therapeutic protein

Oral delivery is the most common method of drug administration with high safety and good compliance for patients. However, delivering therapeutic proteins to the target site via oral route involves tremendous challenge due to unfavourable conditions like biochemical barrier, mucus barrier and epithelial barriers. According to the functional differences of various protein drug delivery systems, the recent advances in pH responsive polymer-based drug delivery system, mucoadhesive polymer-based drug delivery system, absorption enhancers-based drug delivery system and composite polymer-based delivery system all were briefly summarised in this review, which not only clarified the clinic potential of these novel drug delivery systems, but also described the way for increasing oral bioavailability of therapeutic protein.

Development of biocompatible and VEGF-targeted paclitaxel nanodrugs on albumin and graphene oxide dual-carrier for photothermal-triggered drug delivery in vitro and in vivo

In this study, we performed the characterization and synthesis of biocompatible and targeted albumin and graphene oxide (GO) dual-carrier paclitaxel (PTX) nanoparticles for photothermal-triggered tumor therapy. PTX absorbed on GO nanosheets as cores were coated with human serum albumin (HSA), following surface conjugation with monoclonal antibodies (mAb) against vascular endothelial growth factor (VEGF; denoted as mAbVEGF) via polyethylene glycol linker to form targeted nanoparticles (PTX-GHP-VEGF). The spherical nanoparticles were 191±5 nm in size with good stability and biocompatibility. GO functioned as the first carrier and a near infrared absorber that can generate photothermal effects under 5-minute 808-nm laser irradiation to thermal trigger the release of PTX from the second carrier HSA nanoparticles. The mechanism of thermal-triggered drug release was also investigated preliminarily, in which the heat generated by GO induced swelling of PTX-GHP-VEGF nanoparticles which released the drugs. In vitro studies found that PTX-GHP-VEGF can efficiently target human SW-13 adrenocortical carcinoma cells as evaluated by confocal fluorescence microscopy as well as transmission electron microscopy, and showed an obvious thermal-triggered antitumor effect, mediated by apoptosis. Moreover, PTX-GHP-VEGF combined with near infrared irradiation showed specific tumor suppression effects with high survival rate after 100 days of treatment. PTX-GHP-VEGF also demonstrated high biosafety with no adverse effects on normal tissues and organs. These results highlight the remarkable potential of PTX-GHP-VEGF in photothermal controllable tumor treatment.

Conserved Activity of Reassociated Homotetrameric Protein Subunits Released from Mesoporous Silica Nanoparticles

Mesoporous silica nanoparticles (MSN) with enlarged pores were prepared and characterized, and reversibly dissociated subunits of concanavalin A were entrapped in the mesopores, as shown by multiple biochemical and material characterizations. When loaded in the MSN, we demonstrated protein stability from proteases and, upon release, the subunits reassociated into active proteins shown through mannose binding and o-phthalaldehyde fluorescence. We have demonstrated a versatile and facile method to load homomeric proteins into MSN with potential applications in enhancing the delivery of large therapeutic proteins.

Multifunctional and Redox-Responsive Self-Assembled Magnetic Nanovectors for Protein Delivery and Dual-Modal Imaging

Nanoparticle (NP) based model carriers present an emerging strategy for protein delivery. However, constructing a multifunctional nanocarrier with high loading capacity, diagnostic imaging capacity, and controlled release capability is a tremendous challenge for protein delivery systems. Thus, we herein report on the fabrication of redox-responsive magnetic nanovectors (termed RMNs) through self- assembly of Fe₃O₄ NPs and redox-responsive polymer ligands, which could effectively transport protein and trigger intracellular protein release. These RMNs also exhibited low toxicity, high stability, biocompatibility, and T₂-weighted contrast-enhancement properties. In addition, they presented a quantized positively charged surface that had the capacity to load cyanine 5.5 (Cy5.5) labeled human serum albumin (HSA) with high loading efficiency (∼84%) via electrostatic interactions and which favored cellular uptake. Notably, studies of the in vitro protein release showed that HSA-Cy5.5-loaded RMNs (RMNs-HSA-Cy5.5) presented minimal cumulative release behavior under physiological conditions but release was rapidly enhanced under high glutathione concentration conditions. Confocal microscopy further revealed that protein was delivered and localized at the perinuclear region of tumor cells. Moreover, the in vivo imaging results confirmed that RMNs-HSA-Cy5.5 could serve as a dual-modal probe for simultaneous near-infrared fluorescence (NIRF) imaging and magnetic resonance (MR) imaging, which can be used for breast cancer diagnosis, and verified higher tumor accumulation of transported protein in a living body. Overall, we believe that these multifunctional RMNs exhibit great promise for protein delivery, cancer diagnosis and therapy, and multimodal imaging, as well as clinical applications.

Recent progress in drug delivery of pluronic P123: pharmaceutical perspectives

This review focuses on recent investigations that used Pluronic P123 (P123) as pharmaceutical ingredients in vesicle, micelle, mixed micelle, in situ gel, tablet and emulsion. The main results from these studies show that P123 can significantly increase the stability of incorporated hydrophobic drugs with enhanced in vitro cytotoxicity and cellular uptake of anticancer drugs. Moreover, modified forms of P123 with RGD, folate or other targeted marker have shown its therapeutic potentials in various types of tumors and cancers. Furthermore, modified forms of P123 alone and/or mixed with other copolymers have less toxic effects and more tumor-specific delivery of anticancer drugs. They are promising materials as a nanoplatform for the drug delivery. Finally, the future perspectives of the field are briefly discussed.

Emerging Multifunctional NIR Photothermal Therapy Systems Based on Polypyrrole Nanoparticles

Near-infrared (NIR)-light-triggered therapy platforms are now considered as a new and exciting possibility for clinical nanomedicine applications. As a promising photothermal agent, polypyrrole (PPy) nanoparticles have been extensively studied for the hyperthermia in cancer therapy due to their strong NIR light photothermal effect and excellent biocompatibility. However, the photothermal application of PPy based nanomaterials is still in its preliminary stage. Developing PPy based multifunctional nanomaterials for cancer treatment in vivo should be the future trend and object for cancer therapy. In this review, the synthesis of PPy nanoparticles and their NIR photothermal conversion performance were first discussed, followed by a summary of the recent progress in the design and implementation on the mulitifunctionalization of PPy or PPy based therapeutic platforms, as well as the introduction of their exciting biomedical applications based on the synergy between the photothermal conversion effect and other stimulative responsibilities.

In vitro and in vivo sustained release of exenatide from vesicular phospholipid gels for type II diabetes

Diabetes is a chronic disease that requires daily treatment to maintain a stable blood glucose level. Sustained-release formulations can thus benefit the treatment of diabetes by reducing the repeated administration of therapeutics. Our study aimed to develop a sustained-release platform for exenatide that is biocompatible and capable of mass production. Vesicular phospholipid gels (VPGs) are semisolid phospholipid dispersions with controlled release profiles. Exenatide-VPGs prepared via simple magnetic stirring showed excellent biocompatibility with an average particle size of about 15 μm after redispersion. VPGs were shown to achieve sustained release for up to 21 days in vitro with no obvious burst effect. The in vivo release study showed that VPGs sustained the release of the exenatide for up to 11 days. Moreover, after subcutaneous injection of the exenatide-VPGs in the diabetic rats, the hypoglycemic effect lasted for 10 days compared with exenatide solution. In sum, the exenatide-VPGs system represents a promising sustained-release formulation for exenatide with a long-acting therapeutic efficacy in vivo.