Cryo-Milled β-Glucan Nanoparticles for Oral Drug Delivery

Gemcitabine is a nucleoside analog effective against a number of cancers. However, it has an oral bioavailability of less than 10%, due to its high hydrophilicity and low permeability through the intestinal epithelium. Therefore, the aim of this project was to develop a novel nanoparticulate drug delivery system for the oral delivery of gemcitabine to improve its oral bioavailability. In this study, gemcitabine-loaded β-glucan NPs were fabricated using a film-casting method followed by a freezer-milling technique. As a result, the NPs showed a small particle size of 447.6 ± 14.2 nm, and a high drug entrapment efficiency of 64.3 ± 2.1%. By encapsulating gemcitabine into β-glucan NPs, a sustained drug release profile was obtained, and the anomalous diffusion release mechanism was analyzed, indicating that the drug release was governed by diffusion through the NP matrix as well as matrix erosion. The drug-loaded NPs had a greater ex vivo drug permeation through the porcine intestinal epithelial membrane compared to the plain drug solution. Cytotoxicity studies showed a safety profile of the β-glucan polymers, and the IC50s of drug solution and drug-loaded β-glucan NPs were calculated as 228.8 ± 31.2 ng·mL-1 and 306.1 ± 46.3 ng·mL-1, respectively. Additionally, the LD50 of BALB/c nude mice was determined as 204.17 mg/kg in the acute toxicity studies. Notably, pharmacokinetic studies showed that drug-loaded β-glucan NPs could achieve a 7.4-fold longer T1/2 and a 5.1-fold increase in oral bioavailability compared with plain drug solution. Finally, in vivo pharmacodynamic studies showed the promising capability of gemcitabine-loaded β-glucan NPs to inhibit the 4T1 breast tumor growth, with a 3.04- and 1.74-fold reduction compared to the untreated control and drug solution groups, respectively. In conclusion, the presented freezer-milled β-glucan NP system is a suitable drug delivery method for the oral delivery of gemcitabine and demonstrates a promising potential platform for oral chemotherapy.

A novel peptide-drug conjugate for glioma-targeted drug delivery

The existence of the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) greatly limits the application of chemotherapy in glioma. To address this challenge, an optimal drug delivery system must efficiently cross the BBB/BBTB and specifically deliver therapeutic drugs into glioma cells while minimizing systemic toxicity. Here we demonstrated that glucose-regulated protein 78 (GRP78) and dopamine receptor D2 were highly expressed in patient-derived glioma tissues, and dopamine receptors were highly expressed on the BBB. Subsequently, we synthesized a novel "Y"-shaped peptide and compared the effects of different linkers on the receptor affinity and targeting ability of the peptide. A peptide-drug conjugate (pHA-AOHX-VAP-doxorubicin conjugate, pHA-AOHX-VAP-DOX) with a better affinity for glioma cells and higher solubility was derived for glioma treatment. pHA-AOHX-VAP-DOX could cross both BBB and BBTB via dopamine receptor and GRP78 receptor, and finally target glioma cells, significantly prolonging the survival time of nude mice bearing intracranial glioma. Furthermore, pHA-AOHX-VAP-DOX significantly reduced the toxicity of DOX and increased the maximum tolerated dose (MTD). Collectively, this work paves a new avenue for overcoming multiple barriers and effectively delivering chemotherapeutic agents to glioma cells while providing key evidence to identify potential receptors for glioma-targeted drug delivery.

All-stage targeted red blood cell membrane-coated docetaxel nanocrystals for glioma treatment

Challenges for glioma treatment with nanomedicines include physio-anatomical barriers (the blood-brain barrier and blood-brain tumor barrier), low drug loading capacity, and limited circulation time. Here, a red blood cell membrane-coated docetaxel drug nanocrystal (pV-RBCm-NC(DTX)), modified with pHA-VAP (pV) for all-stage targeting of glioma, was designed. The NC(DTX) core exhibited a high drug loading capacity but low in vivo stability, and the RBCm coating significantly enhanced the stability and prolonged in vivo circulation. Moreover, the Y-shaped targeting ligand pV was modified by a mild avidin-biotin interaction, which endowed RBCm-NC(DTX) with superior barrier-crossing ability and therapeutic efficacy. The integration of nanocrystal technology, cell membrane coating, and the avidin-biotin insertion method into this active targeting biomimetic formulation represents a promising drug delivery strategy for glioma.

Intranasal G5-BGG/pDNA Vaccine Elicits Protective Systemic and Mucosal Immunity against SARS-CoV-2 by Transfecting Mucosal Dendritic Cells

Infectious disease pandemics, including the coronavirus disease 2019 pandemic, have heightened the demand for vaccines. Although parenteral vaccines induce robust systemic immunity, their effectiveness in respiratory mucosae is limited. Considering the crucial role of nasal-associated lymphoid tissue (NALT) in mucosal immune responses, in this study, the intranasal complex composed of G5-BGG and antigen-expressing plasmid DNA (pSP), named G5-BGG/pSP complex, is developed to activate NALT and to promote both systemic and mucosal immune defense. G5-BGG/pSP could traverse mucosal barriers and deliver DNA to the target cells because of its superior nasal retention and permeability characteristics. The intranasal G5-BGG/pSP complex elicits robust antigen-specific immune responses, such as the notable production of IgG antibody against several virus variants. More importantly, it induces elevated levels of antigen-specific IgA antibody and a significant expansion of the lung-resident T lymphocyte population. Notably, the intranasal G5-BGG/pSP complex results in antigen expression and maturation of dendritic cells in nasal mucosae. These findings exhibit the potential of G5-BGG, a novel cationic material, as an effective gene carrier for intranasal vaccines to obtain robust systemic and mucosal immunity.

Recent advances in nanocrystal-based technologies applied for ocular drug delivery

INTRODUCTION

The intricate physiological barriers of the eye and the limited volume of eye drops impede efficient delivery of poorly water-soluble drugs. In the last decade, nanocrystals have emerged as versatile drug delivery systems in various administration routes from bench to bedside. The unique superiorities of nanocrystals, mainly embodied in high drug-loading capacity, good mucosal adhesion and penetration, and greatly improved drug solubility, reveal a promising prospect for ocular delivery of poorly water-soluble drugs.

AREAS COVERED

This article focuses on the ophthalmic nanocrystal technologies and products that are in the literature, clinical trials, and even on the market. The recent research progress in the preparation, ocular application, and absorption of nanocrystals are highlighted, and the pros and cons of nanocrystals in overcoming the physiological barriers of the eye are also summarized.

EXPERT OPINION

Nanocrystals have demonstrated success as glucocorticoid eye drops in the treatment of anterior segment diseases. However, the thermodynamic stability of nanocrystals remains the major challenge in product development. New technologies for efficiently optimizing stabilizers and sterilization processes are still expected. Strategies to confer more diverse functions via surface modification are also worth exploration to improve the potential of nanocrystals in delivering poorly water-soluble drugs to posterior segment of the eye.

Erratum: Author correction to 'Amino-functionalized poloxamer 407 with both mucoadhesive and thermosensitive properties: Preparation, characterization and application in vaginal drug delivery system' [Acta Pharm Sin B 7 (2017) 593-602]

[This corrects the article DOI: 10.1016/j.apsb.2017.03.002.].

Targeting cerebral diseases with enhanced delivery of therapeutic proteins across the blood-brain barrier

INTRODUCTION

Cerebral diseases have been threatening public physical and psychological health in the recent years. With the existence of the blood-brain barrier (BBB), it is particularly hard for therapeutic proteins like peptides, enzymes, antibodies, etc. to enter the central nervous system (CNS) and function in diagnosis and treatment in cerebral diseases. Fortunately, the past decade has witnessed some emerging strategies of delivering macromolecular therapeutic proteins across the BBB.

AREAS COVERED

Based on the structure, functions, and substances transport mechanisms, various enhanced delivery strategies of therapeutic proteins were reviewed, categorized by molecule-mediated delivery strategies, carrier-mediated delivery strategies, and other delivery strategies.

EXPERT OPINION

As for molecule-mediated delivery strategies, development of genetic engineering technology, optimization of protein expression and purification techniques, and mature of quality control systems all help to realize large-scale production of recombinant antibodies, making it possible to apply to the clinical practice. In terms of carrier-mediated delivery strategies and others, although nano-carriers/adeno-associated virus (AAV) are also promising candidates for delivering therapeutic proteins or genes across the BBB, some issues still remain to be further investigated, including safety concerns related to applied materials, large-scale production costs, quality control standards, combination therapies with auxiliary delivery strategies like focused ultrasound, etc.

Advance in Nanomedicine for Improving Mucosal Penetration and Effective Therapy of Cervical Cancer

Insufficient intratumor drug distribution and serious adverse effects are often associated with systemic chemotherapy for cervical cancer. Considering the location of cervical cancer, access to the cervix through the vagina may provide an alternative administration route for high drug amounts at the tumor site, minimal systemic exposure as well as convenience of non-invasive self-medication. Enormous progress has been made in nanomedicine to improve mucosal penetration and enhance the effectiveness of therapy for cervical cancer. This review article first introduce the physiological state of cervicovaginal cavity and the characteristics of intravaginal environment in cervical cancers. Based on introduction to the physiological state of cervicovaginal cavity and the characteristics of intravaginal environment in cervical cancers, both "first mucus-adhering then mucosal penetration" and "first mucus-penetrating then mucosal penetration" strategies are discussed with respect to mechanism, application condition, and examples. Finally, existing challenges and future directions are envisioned in the rational design, facile synthesis, and comprehensive utilization of nanomedicine for local therapy of cervical cancer. This review is expected to provide useful reference information for future research on nanomedicine for intravaginally administered formulations for topical treatment of cervical cancer.

[Prediction of protection probability against Omicron BA.1, BA.4 and BA.5 variants in symptomatic infections with prototype strain based on neutralization antibody levels]

Objective: To predict the protection probability of different clinical outcomes after reinfection with Omicron variant in symptomatic and unvaccinated COVID-19 patients who infected with prototype strain. Methods: The data used in this study were derived from a systematic review and meta-analysis which systematically searched PubMed, Embase, Web of Science, and Europe PMC databases, included published and uploaded studies of dynamic changes of neutralizing antibodies in symptomatic COVID-19 patients from 1 January 2020 to 2 October 2022 and extracted the literature information, study design, serological experiment information and antibody results. According to the scatter distribution characteristics of antibody titer data, a generalized additive model based on Gaussian distribution was used to fit the titer value of neutralizing antibody based on logarithmic conversion and the dynamic change pattern of neutralizing antibody in symptomatic and unvaccinated COVID-19 patients infected with prototype strain over time was obtained. In this study, the fitted antibody titers of patients on the 28th, 51st, and 261st day after symptom onset was selected to predict the protection probability. Results: Neutralizing antibodies produced in symptomatic and unvaccinated patients infected with prototype strain could provide protection against Omicron reinfection, and the probability of protection gradually decreased with time. Neutralizing antibody level on day 28 after symptom onset provided protection probability of 30.3% (95%CI: 20.0%-45.5%) against reinfection, 51.5% (95%CI: 33.4%-75.9%) against symptomatic reinfection, and 91.2% (95%CI: 77.1%-97.7%) against severe reinfection caused by Omicron BA.5. The protection probability against Omicron BA.1, BA.4 and BA.5 reinfections decreased significantly 261 days after symptom onset, showing 9.6%-12.9%, 18.4%-23.9% and 63.1%-70.3% against three clinical outcomes, respectively. At the same time point and against the same clinical outcome, the protection probability of BA.1 was the highest, followed by BA.4 and BA.5. Conclusions: Neutralizing antibodies induced in symptomatic and unvaccinated COVID-19 patients previously infected with the prototype strain have limited protection probability against Omicron BA.5 reinfections and symptomatic reinfections. The protection probability against Omicron BA.5 reinfections is 30.3% 28 days after symptom onset and decreases to about 10% after 261 days. However, the protection probability against severe reinfections is considerable, with over 90% 28 days after symptom onset and still exceeding 60% after 261 days.

Ocular therapies with biomacromolecules: From local injection to eyedrop and emerging noninvasive delivery strategies

The last two decades have witnessed a continuously increasing number of biomacromolecules approved for the treatment of ocular diseases. The eye possesses multiple protective mechanisms to resist the invasion of exogenous substances, but meanwhile these physiological defense systems also act as strong barriers, impeding absorption of most biomacromolecules into the eye. As a result, local injections play predominant roles for posterior ocular delivery of biomacromolecules in clinical practice. To achieve safe and convenient application of biomacromolecules, alternative strategies to realize noninvasive intraocular delivery are necessary. Various nanocarriers, novel penetration enhancers and physical strategies have been explored to facilitate delivery of biomacromolecules to both anterior and posterior ocular segments but still suffered difficulties in clinical translation. This review compares the anatomical and physiological characteristics of the eyes from those frequently adopted experimental species and profiles the well-established animal models of ocular diseases. We also summarize the ophthalmic biomacromolecules launched on the market and put emphasis on emerging noninvasive intraocular delivery strategies of peptides, proteins and genes.

Biological evaluation of a novel stable peptide PET molecular probe [18F]AlF-NOTA-DVAP targeting to tumor cell surface GRP78

BACKGROUNDS

Glucose-Regulated Protein 78 (GRP78) is an attractive anticancer target for its selective anchoring on the surface of tumor cells and cancer endothelial cells rather than normal cells. Cell-surface GRP78 overexpression of tumor indicates that GRP78 is a crucial target for relative tumor imaging and clinical treatment. Herein, we report the design and preclinical evaluation of a new D peptide ligand [¹⁸F]AlF-NOTA-^DVAP recognizing GRP78 expressed on the cell surface of breast cancer.

METHODS

Radiochemical synthesis of [¹⁸F]AlF-NOTA-^DVAP was achieved via a one-pot labeling process by heating NOTA-^DVAP in the presence of in situ prepared [¹⁸F]AlF for 15 min at 110 °C and purified through HPLC.

RESULTS

The radiotracer showed high in vitro stability in rat serum at 37 °C over 3 h. Both biodistribution studies and in vivo micro-PET/CT imaging studies in BALB/c mice bearing 4 T1 tumor showed [¹⁸F]AlF-NOTA-^DVAP had a rapid and high uptake in tumor, as well as a long residence time. The high hydrophilicity of the radiotracer enables its fast clearance from most normal tissues and thus improves the tumor-to-normal tissue ratios (4.40 at 60 min) which is better than [¹⁸F]FDG (1.31 at 60 min). Pharmacokinetic studies showed the average in vivo mean residence time of the radiotracer was just 0.6432 h and indicated that this hydrophilic radiotracer was quickly eliminated from the body to reduce the distribution of non-target tissues.

CONCLUSIONS

These results suggest that [¹⁸F]AlF-NOTA-^DVAP is a very promising PET probe for tumor-specific imaging of cell-surface GRP78-positive tumor.

Influence of lung cancer model characteristics on tumor targeting behavior of nanodrugs

Evidence is mounting that there is a significant gap between the antitumor efficacy of nanodrugs in preclinical mouse tumor models and in clinical human tumors, and that differences in tumor models are likely to be responsible for this gap. Herein, we investigated the enhanced permeability and retention (EPR) effect in mouse lung cancer models with different tumor growth rates, volumes and locations, and analyzed the nanodrug tumor targeting behaviors limited by tumor vascular pathophysiological characteristics in various tumor models. The results showed that the fast-growing tumors were characterized by lower vascular tight junctions, leading to higher vascular paracellular transport activity and nanodrug tumor accumulation. The paracellular transport activity increased with the growth of tumor, but the vascular density and transcellular transport activity decreased, and as a result, the average tumor accumulation of passive targeting nanodrugs decreased. Orthotopic tumors were rich in blood vessels, but had low vascular transcellular and paracellular transport activities, making it difficult for nanodrug accumulation in orthotopic tumors via passive targeting strategies. The antitumor efficacy of passive targeting nanodrugs in various lung cancer-bearing mice validated the aforementioned nanodrug accumulation behavior, and nanodrugs based on the angiogenesis-tumor sequential targeting strategy achieved obviously improved efficacy in orthotopic lung cancer-bearing mice. These results suggest that the EPR effect varies in different tumor models and should not be used as a universal targeting strategy for antitumor nanodrugs. Besides, attention should be paid to the animal tumor models in the evaluation of nanodrugs so as to avoid exaggerating the antitumor efficacy.

All-stage targeted therapy for the brain metastasis from triple-negative breast cancer

Brain metastasis is a common and serious complication of breast cancer, which is commonly associated with poor survival and prognosis. In particular, the treatment of brain metastasis from triple-negative breast cancer (BM-TNBC) has to face the distinct therapeutic challenges from tumor heterogeneity, circulating tumor cells (CTCs), blood-brain barrier (BBB) and blood-tumor barrier (BTB), which is in unmet clinical needs. Herein, combining with the advantages of synthetic and natural targeting moieties, we develop a "Y-shaped" peptide pVAP-decorated platelet-hybrid liposome drug delivery system to address the all-stage targeted drug delivery for the whole progression of BM-TNBC. Inherited from the activated platelet, the hybrid liposomes still retain the native affinity toward CTCs. Further, the peptide-mediated targeting to breast cancer cells and transport across BBB/BTB are demonstrated in vitro and in vivo. The resultant delivery platform significantly improves the drug accumulation both in orthotopic breast tumors and brain metastatic lesions, and eventually exhibits an outperformance in the inhibition of BM-TNBC compared with the free drug. Overall, this work provides a promising prospect for the comprehensive treatment of BM-TNBC, which could be generalized to other cell types or used in imaging platforms in the future.

Drug Nanocrystals for Active Tumor-Targeted Drug Delivery

Drug nanocrystals, which are comprised of active pharmaceutical ingredients and only a small amount of essential stabilizers, have the ability to improve the solubility, dissolution and bioavailability of poorly water-soluble drugs; in turn, drug nanocrystal technology can be utilized to develop novel formulations of chemotherapeutic drugs. Compared with passive targeting strategy, active tumor-targeted drug delivery, typically enabled by specific targeting ligands or molecules modified onto the surface of nanomedicines, circumvents the weak and heterogeneous enhanced permeability and retention (EPR) effect in human tumors and overcomes the disadvantages of nonspecific drug distribution, high administration dosage and undesired side effects, thereby contributing to improving the efficacy and safety of conventional nanomedicines for chemotherapy. Continuous efforts have been made in the development of active tumor-targeted drug nanocrystals delivery systems in recent years, most of which are encouraging and also enlightening for further investigation and clinical translation.

In vivo self-assembled drug nanocrystals for metastatic breast cancer all-stage targeted therapy

Chemotherapy is still the mainstay treatment for metastatic triple-negative breast cancers (TNBC) currently in clinical practice. The unmet needs of chemotherapy for metastatic TNBC are mainly from the insufficient drug delivery and unavailable targeting strategy that thwart the whole progression of metastatic TNBC. The in vivo ligands-mediated active targeting efficiency is usually affected by protein corona. While, the protein corona-bridged natural targeting, in turn, provides a new way for specific drug delivery. Herein, we develop a novel metastatic progression-oriented in vivo self-assembled Cabazitaxel nanocrystals (CNC) delivery system (PC/CNC) through the CNC automatically absorbing functional plasma proteins (transferrin, apolipoprotein A-IV and apolipoprotein E) in vivo, aiming to achieve the simultaneously targeted delivery to primary tumors, circulating tumor cells and metastatic lesions. With the unique advantages of superhigh drug-loading and protein corona empowered active targeting properties to tumor cells, HUVECs, active-platelets and blood-brain barrier/blood-tumor barrier, the PC/CNC exhibits a significantly improved therapeutic effect in metastatic TNBC therapy compared with free drug and CNC-loaded liposomes.

All-stage targeted therapy for glioblastoma based on lipid membrane coated cabazitaxel nanocrystals

Glioblastoma (GBM) is the most aggressive brain tumor with poor prognosis and frequent recurrence. The blood-brain barrier (BBB), blood-brain tumor barrier (BBTB) hinder the entry of therapeutics into the glioma region. Vasculogenic mimicry (VM) formed by invasive glioma cells is also related to recurrence of GBM. VAP is a D-peptide ligand of GRP78 protein overexpressed on BBTB, VM, and glioma cells but not on normal tissues. Besides, p-hydroxybenzoic acid (pHA) can effectively traverse the BBB. Herein we developed an all-stage glioma-targeted cabazitaxel (CBZ) nanocrystal loaded liposome modified with a "Y" shaped targeting ligand composed of pHA and VAP (pV-Lip/cNC). The pure drug nanocrystal core provided high drug loading, while lipid membrane promoted the stability and circulation time. pV-Lip/cNC exhibited excellent glioma homing, barriers crossing, and tumor spheroid penetrating capability in vitro. Treatment of pV-Lip/cNC displayed enhanced CBZ accumulation in glioma and anti-glioma effect with a median survival time (53 days) significantly longer than that of cNC loaded liposomes modified with either single ligand (42 days for VAP and 45 days for pHA) in the murine orthotopic GBM model. These results indicated pV-Lip/cNC could traverse the BBB and BBTB, destruct VM, and finally kill glioma cells to realize all-stage glioma therapy.

Engineered platelets-based drug delivery platform for targeted thrombolysis

Thrombolytic agents have thus far yielded limited therapeutic benefits in the treatment of thrombotic disease due to their short half-life, low targeting ability, and association with serious adverse reactions, such as bleeding complications. Inspired by the natural roles of platelets during thrombus formation, we fabricated a platelet-based delivery system (NO@uPA/PLTs) comprising urokinase (uPA) and arginine (Arg) for targeted thrombolysis and inhibition of re-embolism. The anchoring of uPA to the platelet surface by lipid insertion increased the thrombotic targeting and in vivo circulation duration of uPA without disturbing platelet functions. Nitric oxide (NO) generated by the loaded Arg inhibited platelet aggregation and activation at the damaged blood vessel, thereby inhibiting re-embolism. NO@uPA/PLTs effectively accumulated at the thrombi in pulmonary embolism and carotid artery thrombosis model mice and exerted superior thrombolytic efficacy. In addition, the platelet delivery system showed excellent thrombus recurrence prevention ability in a mouse model of secondary carotid artery injury. The coagulation indicators in vivo showed that the platelet-based uPA and NO co-delivery system possessed a low hemorrhagic risk, providing a promising tool for rapid thrombolysis and efficient inhibition of posttreatment re-embolism.

Facile Separation of PEGylated Liposomes Enabled by Anti-PEG scFv

PEGylated nanocarriers have gained increasing attention due to reduced toxicity and enhanced circulation compared with free drugs. According to guidances of drug regulatory departments worldwide, it is crucial to determine free and liposomal drug concentrations; however, the conventional used separation methods including dialysis, ultrafiltration, and solid-phase extraction (SPE) have drawbacks of time-consuming, drug leakage, environmental pollution or error bias of trace level drug. Here we developed a facile PEG-scFv-based separation method combined with HPLC to quantify free doxorubicin (DOX) and liposomal DOX in plasma. Anti-PEG single chain variable fragment antibody (PEG-scFv) was adopted to sediment PEGylated liposomes by simple incubation and low speed centrifugation. Compared to SPE, it demonstrated sufficient accuracy and sensitivity to evaluate free and liposomal DOX with intact liposomes. Therefore, it can serve as an alternative approach of SPE, which is suitable for quality assessment and pharmacokinetics evaluation of PEGylated liposomal drugs and possible other PEGylated nanocarriers.

N-trimethyl chitosan coated nano-complexes enhance the oral bioavailability and chemotherapeutic effects of gemcitabine

N-trimethyl chitosan (TMC) is a multifunctional polymer that can be used in various nanoparticle forms in the pharmaceutical, nutraceutical and biomedical fields. In this study, TMC was used as a mucoadhesive adjuvant to enhance the oral bioavailability and hence antitumour effects of gemcitabine formulated into nanocomplexes composed of poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) conjugated with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS). A central composite design was applied to achieve the optimal formulation. Cellular uptake and drug transportation studies revealed the nanocomplexes permeate over the intestinal cells via adsorptive-mediated and caveolae-mediated endocytosis. Pharmacokinetic studies demonstrated the oral drug bioavailability of the nanocomplexes was increased 5.1-fold compared with drug solution. In pharmacodynamic studies, the formulation reduced tumour size 3.1-fold compared with the drug solution. The data demonstrates that TMC modified nanocomplexes can enhance gemcitabine oral bioavailability and promote the anticancer efficacy.

Hydrogel loading functionalized PAMAM/shRNA complex for postsurgical glioblastoma treatment

Glioblastoma, the most common malignant tumor of the central nervous system, readily relapses after surgery. Based on the CD47-SIRPα axis, we designed and implanted a thermo-sensitive hydrogel loaded with a gene complex into the postoperative cavity to inhibit the immune escape of residual tumor cells after surgery. A novel non-viral vector, G5-BGG, was synthesized and formed into a gene complex with shRNA plasmid. Our results showed that the G5-BGG/shRNA871 complex downregulated CD47 protein expression, leading to enhanced phagocytosis of U87MG cells by marrow-derived macrophages. G5-BGG/pDNA complex was loaded into a poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-PEG-PLGA) hydrogel. Studies confirmed that the G5-BGG/pDNA complex remained integrated in the hydrogel and was sustainably released for up to 7 days. In an in vivo orthotopic U87MG postoperative tumor model, G5-BGG/shRNA871-loaded hydrogel combined with temozolomide downregulated CD47 protein expression, increased macrophage infiltration into residual tumors, and significantly prolonged the survival time of mice, indicating potential applications for glioblastoma treatment.

Interrogating preclinical study of liposomes: The effect of mouse strain reexamined

Mice are arguably the most important tool in the preclinical evaluation of liposomes; however, the effects of inter-strain physiological variabilities on in vivo performance of liposomes have been seriously overlooked. The present study validated that plasma proteins (PPs) and the capability of mononuclear phagocyte system (MPS) (typically expressed by phagocytosis rate, K) were mice strain-dependent. Physiological variabilities in PPs and the phagocytosis rate jointly contributed to the inter-strain inconsistency of pharmacokinetic (PK) profiles of liposomes. For the PPs sensitive liposomes (such as plain PEGylated liposomes and folic acid functionalized PEGylated liposomes), inter-strain variabilities in PK profiles could be calibrated using the corrected phagocytic rate (K_C = K×(c × Ig)/(alb×apo)), where c, Ig, alb and apo were respective the total content of complement proteins, immunoglobulins, albumin and apolipoproteins. While for the PPs insensitive liposomes (e.g., cRGD functionalized liposomes), phagocytic rate could be directly used to calibrate inter-strain difference of liposome PK profiles. Our data also warn that the reciprocal interaction between payloads and organisms would be much more complicated than that between liposomes and organisms, thus independent investigation should be conducted for each individual therapeutic agent.

Deciphering Protein Corona by scFv-Based Affinity Chromatography

It remains challenging to precisely decipher the structural and functional characteristics of protein coronas. To overcome the drawbacks frequently occurring in the traditional separation methods, an anti-PEG single-chain variable fragment (PEG-scFv) based affinity chromatography (AfC) was developed to achieve precise and efficient separation of protein coronas on PEGylated liposomes (sLip). His-tagged PEG-scFv could readily capture sLip without affecting protein corona compositions, and separate sLip/protein complex from plasma protein aggregates and endogenous vesicles through the Ni-NTA column. AfC demonstrated 43-fold higher protein corona collecting efficiency than centrifugation, which was extremely crucial for separation of in vivo protein coronas due to the limitation of sample size. AfC evaded contamination by endogenous vesicles and protein aggregates occurring in centrifugation, and reserved the loosely bound proteins, providing an unprecedented approach to deeply decipher protein coronas. The scFv-based AfC also paves new avenues for the separation of protein coronas formed on other nanomedicines.

Pancreatic Cancer: Recent Progress of Drugs in Clinical Trials

Pancreatic cancer is a highly malignant tumor and one of the primary causes of cancer-related death. Because pancreatic cancer is difficult to diagnose in the early course of the disease, most patients present with advanced lesions at the time of diagnosis, and only 20% of patients are eligible for surgery. Consequently, drug treatment has become extremely important. At present, the main treatment regimens for pancreatic cancer are gemcitabine and the FORFIRINOX and MPACT regimens. However, none of these regimens substantially improves the prognosis of patients with pancreatic cancer. Extensive efforts have been dedicated to the study of pancreatic cancer in recent years. With the development and clinical application of biological targeted drugs, the biological targeted treatment of tumors has been widely accepted. Therefore, this article used relevant clinical trial data to summarize the research progress of traditional chemotherapy drugs and biological targeted drugs for the treatment of pancreatic cancer.

Unraveling GLUT-mediated transcytosis pathway of glycosylated nanodisks

Glucose transporter (GLUT)-mediated transcytosis has been validated as an efficient method to cross the blood-brain barrier and enhance brain transport of nanomedicines. However, the transcytosis process remains elusive. Glycopeptide-modified nanodisks (Gly-A7R-NDs), which demonstrated high capacity of brain targeting via GLUT-mediated transcytosis in our previous reports, were utilized to better understand the whole transcytosis process. Gly-A7R-NDs internalized brain capillary endothelial cells mainly via GLUT-mediated/clathrin dependent endocytosis and macropinocytosis. The intracellular Gly-A7R-NDs remained intact, and the main excretion route of Gly-A7R-NDs was lysosomal exocytosis. Glycosylation of nanomedicine was crucial in GLUT-mediated transcytosis, while morphology did not affect the efficiency. This study highlights the pivotal roles of lysosomal exocytosis in the process of GLUT-mediated transcytosis, providing a new impetus to development of brain targeting drug delivery by accelerating lysosomal exocytosis.

Interrogation of Folic Acid-Functionalized Nanomedicines: The Regulatory Roles of Plasma Proteins Reexamined

Folic acid (FA) has been extensively exploited to facilitate targeted delivery of nanomedicines by recognizing the folate receptor-α (FR-α) overexpressed in many human cancers. Unfortunately, none have been approved for clinical use yet. Here we reveal that FA functionalization induces heavy natural IgM absorption on the liposomal surface, depriving FA of receptor recognition and accelerating complement activation in vivo. FA functionalization does not enhance distribution of liposomes in FR-α-overexpressed tumors in comparison to plain liposomes (without FA), but leads to aggravated capture of liposomes by macrophages in the tumor, liver, and spleen. In addition, FA-functionalized polymeric nanoparticles are also vulnerable to natural IgM absorption. This work highlights the pivotal roles of natural IgM in regulating in vivo delivery of FA-functionalized nanomedicines. Due to the prevalent association of immune disorders and varying levels of immunoglobulins with cancer patients, extraordinary cautiousness is urged for clinical translation of FA-enabled targeted delivery systems.

Treatment of Lung Cancer by Peptide-Modified Liposomal Irinotecan Endowed with Tumor Penetration and NF-κB Inhibitory Activities

Current chemotherapy for lung cancer achieved limited efficacy due to poor tumor targeting and tissue penetration. Another obstacle in the therapy is activated nuclear factor-κB (NF-κB) in tumor cells, which plays a crucial role in promotion of antiapoptosis and drug resistance. In this study, we utilized a multifunctional liposome loaded with irinotecan and surface modified with a cell-permeable NF-κB inhibitor (CB5005), for treatment of non-small-cell lung carcinoma. CB5005 downregulated the level of NF-κB-related protein in the nuclei of A549 cells, and increased cellular uptake of the modified liposomes. In vivo antitumor activity in mice bearing A549 xenografts revealed that modification with CB5005 significantly improved the tumor inhibition rate of irinotecan. Immunohistochemical assays showed that the tumors treated with CB5005-modified liposomes possessed the most apoptotic cells and the lowest level of p50 in the cell nuclei. These results strongly suggest that antitumor efficacy of the irinotecan liposomes can be enhanced by tumor-penetrating and NF-κB-inhibiting functions of CB5005. Consequently, CB5005-modified liposomes provide a possible synergistic therapy for lung cancer, and would also be appropriate for other types of tumors associated with elevated NF-κB activity.

Inhibition of post-trabeculectomy fibrosis via topically instilled antisense oligonucleotide complexes co-loaded with fluorouracil

Trabeculectomy is the mainstay of surgical glaucoma treatment, while the success rate was unsatisfying due to postoperative scarring of the filtering blebs. Clinical countermeasures for scar prevention are intraoperative intervention or repeated subconjunctival injections. Herein, we designed a co-delivery system capable of transporting fluorouracil and anti-TGF-β2 oligonucleotide to synergistically inhibit fibroblast proliferation via topical instillation. This co-delivery system was built based on a cationic dendrimer core (PAMAM), which encapsulated fluorouracil within hydrophobic cavity and condensed oligonucleotide with surface amino groups, and was further modified with hyaluronic acid and cell-penetrating peptide penetratin. The co-delivery system was self-assembled into nanoscale complexes with increased cellular uptake and enabled efficient inhibition on proliferation of fibroblast cells. In vivo studies on rabbit trabeculectomy models further confirmed the anti-fibrosis efficiency of the complexes, which prolonged survival time of filtering blebs and maintained their height and extent during wound healing process, exhibiting an equivalent effect on scar prevention compared to intraoperative infiltration with fluorouracil. Qualitative observation by immunohistochemistry staining and quantitative analysis by Western blotting both suggested that TGF-β2 expression was inhibited by the co-delivery complexes. Our study provided a potential approach promising to guarantee success rate of trabeculectomy and prolong survival time of filtering blebs.

Platelet membrane-functionalized nanoparticles with improved targeting ability and lower hemorrhagic risk for thrombolysis therapy

Intravenous injection of thrombolytic drugs is the most effective strategy for the treatment of thrombotic diseases. However, the clinical application of most thrombolytic drugs is limited by hemorrhagic risks and narrow therapeutic index. The targeted drug delivery systems may help to address these problems. Inspired by the crucial role of platelets in the process of thrombus, Platelet membrane-coated PLGA cores loading lumbrokinase (PNPs/LBK) were designed for effective thrombolysis with reduced hemorrhagic risk. Using a mouse carotid thrombosis model, the affinity of platelet membrane-coated nanoparticles to the thrombus was confirmed. Also, the PNPs/LBK exhibited excellent thrombolytic efficacy at a low dose, compared with free LBK. More importantly, PNPs/LBK showed less adverse effect on the function of the coagulation system, and thus reduced hemorrhagic risk. These results indicated that a promising thrombus-targeted drug delivery system was achieved by coating PLGA nanoparticles with platelet membrane. Such rationally designed drug delivery system will provide a broad platform for thrombus treatment.

The influx/efflux mechanisms of d-peptide ligand of nAChRs across the blood-brain barrier and its therapeutic value in treating glioma

A d-peptide ligand of the nicotine acetylcholine receptors (nAChRs), termed ^DCDX, enables drug delivery to the brain when incorporated into liposomes and has shown promise as a nanocarrier for treating brain diseases. However, few reports have described the mechanisms whereby ^DCDX-modified liposomes traverse the blood-brain barrier (BBB). Here, we studied the molecular mechanisms enabling ^DCDX (and its associated liposomes) to cross an in vitro BBB using a simulated cerebral endothelium monolayer formed by brain capillary endothelial cells (bEnd.3 cells). We also examined the mechanisms whereby ^DCDX-modified liposomes cross the BBB in vivo using the brain efflux-index method. Transport of ^DCDX and its modified liposomes was dominantly mediated via the lipid raft/caveolae endocytic pathway. Both the endoplasmic reticulum (ER) and Golgi complex participated in delivering ^DCDX-modified liposomes to the plasma membrane (PM). ^DCDX-modified liposomes also participated in the endosome/lysosome pathway (with high-efficiency BBB crossing observed in vitro), while competing for the ER/Golgi/PM pathway. In addition, nAChR α7 did not promote the transportation of ^DCDX-modified liposomes in vivo or in vitro, as assessed with α7-knockout mice and by performing α-bungarotoxin (α-Bgt) binding-competition experiments. P-glycoprotein (P-gp) was identified as the main efflux transporter across the BBB, in vivo and in vitro. Using a xenograft nude mouse model of human glioblastoma multiforme, blocking the efflux function of P-gp with verapamil enhanced the therapeutic efficiency of ^DCDX-modified liposomes that were formulated with doxorubicin against glioblastoma. The findings of this study reveal novel mechanisms underlying crossing of the BBB by ^DCDX-modified liposomes, suggesting that ^DCDX-modified liposomes can potentially serve as a powerful therapeutic tool for treating glioma.

Factors Influencing the Immunogenicity and Immunotoxicity of Cyclic RGD Peptide-Modified Nanodrug Delivery Systems

c(RGDyK)-modified liposomes have been shown to be immunogenic and potentially trigger acute systemic anaphylaxis upon repeated intravenous injection in both BALB/c nude mice and ICR mice. However, questions concerning the potential influence of mouse strains, immunization routes, drug carrier properties, and changes in c(RGDyK) itself on the immunogenicity and resultant immunotoxicity (anaphylaxis) of cyclic RGD peptide-modified nanodrug delivery systems remain unanswered. Here, these potential impact factors were investigated, aiming to better understand the immunological properties of cyclic RGD peptide-based nanodrug delivery systems and seek for solutions for this immunogenicity-associated issue. It was revealed that anaphylaxis caused by intravenous c(RGDyK)-modified drug delivery systems might be avoided by altering the preimmunization route (i.e., subcutaneous injection), introducing positively charged lipids into the liposomes and by using micelles or red blood cell membrane (RBC)-based drug delivery systems as the carrier. Different murine models showed different incidences of anaphylaxis following intravenous c(RGDyK)-liposome stimulation: anaphylaxis was not observed in both SD rats and BALB/c mice and was less frequent in C57BL/6 mice than that in ICR mice. In addition, enlarging the peptide ring of c(RGDyK) by introducing amino sequence serine-glycine-serine reduced the incidence of anaphylaxis post the repeated intravenous c(RGDyKSGS)-liposome stimulation. However, immunogenicity of cyclic RGD-modified drug carriers could not be reversed, although some reduction in IgG antibody production was observed when ICR mice were intravenously stimulated with c(RGDyK)-modified micelles, RBC membrane-based drug delivery systems and c(RGDyKSGS)-liposomes instead of c(RGDyK)-liposomes. This study provides a valuable reference for future application of cyclic RGD peptide-modified drug delivery systems.

Guanidyl and imidazolyl integration group-modified PAMAM for gastric adenocarcinoma gene therapy

BACKGROUND

Gene therapy has become a potential strategy for cancer treatment. However, the development of efficient gene vectors restricts the application for cancer gene treatment. Functionalization of polymers with functional groups can significantly improve their transfection efficacy.

METHODS

Guanidyl can form bidentate hydrogen with the phosphate groups and phosphate groups are present in DNA and cell membranes, thus increasing DNA condensation and cellular uptake. Imidazolyl has high buffering capacity in endosomal/lysosomal acidic environment, facilitating endosome/lysosome escape. We designed a structure-integrated group of guanidyl and imidazolyl, 2-aminoimidazole (AM), which was conjugated to PAMAM generation 2 (G2) for gene therapy of gastric adenocarcinoma.

RESULTS

Molecular docking results illustrated that G2-AM bound with DNA molecule effectively via multiple interactions. A quantitative luciferase assay showed that the transfection efficacy of G2-AM/pGL3 was approximately 100-fold greater than that of G2/pGL3, 90-fold greater than that of imidazolyl-modified G2 (G2-M) /pGL3 and 100-fold greater than that of G5/pGL3 without additional cytotoxicity. After introducing the pTRAIL gene into gastric adenocarcinoma cells, the apoptosis ratio of gastric adenocarcinoma cells treated with G2-AM/pTRAIL was 36.95%, which is much larger than the corresponding ratio of G2/pTRAIL (7.45%), G2-M/pTRAIL (11.33%) and G5/pTRAIL (23.2%). In a gastric adenocarcinoma xenograft model, the in vivo transfection efficacy of G2-AM/pRFP was much greater than that of G2/pRFP and G2-M/pRFP.

CONCLUSIONS

These results demonstrate that AM could be modified with cationic polymers for potential application in gene delivery and gastric adenocarcinoma gene therapy.

ɑvβ3-targeted liposomal drug delivery system with attenuated immunogenicity enabled by linear pentapeptide for glioma therapy

Owing to the binding capacity to ɑ_vβ₃ integrin overexpressed on glioma, vasculogenic mimicry and neovasculature, the peptide c(RGDyK) has been exploited pervasively to functionalize nanocarriers for targeted delivery of bioactives. The former study in our group substantiated the immunotoxicity of c(RGDyK)-modified liposome, and this unfavorable immunogenicity is known to compromise blood circulation, targeting efficacy and therapeutic outcome. Therefore, we need to find a superior alternative ligand in order to evade the exquisite immuno-sensitization. We developed mn by structure-guided peptide design and retro-inverso isomerization technique, which was experimentally substantiated to have exceptional binding affinity to ɑ_vβ₃ integrin. Besides mn does not have affinity toward normal liver cells and kidney cells, which c(RGDyK) possesses in a certain degree. Warranting that mn and c(RGDyK) anchored ɑ_vβ₃, we formulated peptide-tethered liposomes and investigated in vivo bio-fate. Compared with c(RGDyK)-modified liposome, mn-modified liposome presented longer blood circulation and reduced ingestion by Kupffer cells with decreased retention in liver accordingly, benefitting from attenuated anti-liposome IgG and IgM response elicited by multiple sequential doses. Those merits strengthened the anti-glioma efficacy of ɑ_vβ₃-targeted doxorubicin-loaded liposomes, proving the importance of immunocompatibility in process of targeted drug delivery.

All-stage precisional glioma targeted therapy enabled by a well-designed D-peptide

Uncontrollable cell proliferation and irreversible neurological damage make glioma one of the most deadly diseases in clinic. Besides the multiple biological barriers, glioma stem cells (GSCs) that are responsible for the maintenance and recurrence of tumor tissues also hinder the therapeutic efficacy of chemotherapy. Therefore, all-stage precisional glioma targeted therapy regimens that could efficiently deliver drugs to glioma cells and GSCs after overcoming multiple barriers have received increasing scrutiny. Methods: A polymeric micelle-based drug delivery system was developed by modifying a "Y-shaped" well-designed ligand of both GRP78 protein and quorum sensing receptor to achieve all-stage precisional glioma targeting, then we evaluated the targeting ability and barrier penetration ability both in vitro and in vivo. In order to achieve all-stage precisional therapy, we need kill both GSCs and glioma related cells. Parthenolide (PTL) has been investigated for its selective toxicity to glioma stem cells while Paclitaxel (PTX) and Temozolomide (TMZ) are widely used in experimental and clinical therapy of glioma respectively. So the in vivo anti-glioma effect of combination therapy was evaluated by Kaplan-Meier survival analysis and immunohistochemical (IHC) examination of tumor tissues. Results: The "Y-shaped" well-designed peptide, termed ^DWVAP, exhibited excellent glioma (and GSCs) homing and barrier penetration ability. When modified on micelle surface, ^DWVAP peptide significantly enhanced accumulation of micelles in brain and glioma. In addition, ^DWVAP micelles showed no immunogenicity and cytotoxicity, which could guarantee their safety when used in vivo. Treatment of glioma-bearing mice with PTL loaded ^DWVAP modified PEG-PLA micelles plus PTX loaded ^DWVAP modified PEG-PLA micelles or PTL loaded ^DWVAP modified PEG-PLA micelles plus TMZ showed improved anti-tumor efficacy in comparison to PTL and PTX loaded unmodified micelles or PTL loaded unmodified micelles plus TMZ. Conclusion: Combination of all-stage targeting strategy and concomitant use of chemotherapeutics and stem cell inhibitors could achieve precise targeted therapy for glioma.

Baicalein enhances the antitumor efficacy of docetaxel on nonsmall cell lung cancer in a β-catenin-dependent manner

The side effects of docetaxel have limited its antitumor performances in the treatment of nonsmall cell lung cancer (NSCLC). To address the problem, baicalein, a bioactive flavone that exhibits antitumor activity, was combined with docetaxel so as to achieve better efficacy and lower toxicity. The combination treatment enhanced the stabilization of microtubules and halted the cell-cycle progression, thus synergistically inhibiting the proliferation and inducing the apoptosis of A549 cells and Lewis lung carcinoma cells. The decreased expression of Cyclin-dependent kinase 6 and Cyclin B1 confirmed its regulation in cell cycle, with β-catenin being an important upstream effector, as evidenced by the decreased expression in the cytoplasm and nucleus as well as the attenuated aggregation in the nucleus. Furthermore, baicalein plus docetaxel evinced better antitumor efficacy by the suppressed tumor growth, increased apoptosis, and decreased tumor angiogenesis in vivo, with no increased toxicity discovered in both tumor-bearing and non-tumor-bearing mice, and an improvement in therapeutic index. This study has demonstrated that baicalein plus docetaxel is an appropriate combination simultaneously with augmented antitumor efficacy and acceptable safety, which might be a promising strategy for patients with advanced NSCLC.

Octopus-like Flexible Vector for Noninvasive Intraocular Delivery of Short Interfering Nucleic Acids

Gene therapy is promising for chronic posterior ocular diseases, which are causal factors for severe vision impairment and even blindness worldwide. However, the inherent absorption barriers of the eye restrict intraocular delivery of therapeutic nucleic acids via topical instillation. Safe and efficient nonviral vectors for ocular gene therapy are still unmet clinical desires. Herein, an octopus-like flexible multivalent penetratin (MVP) was designed to facilitate condensation and delivery of therapeutic nucleic acids using multiarm polyethylene glycol (PEG) as a core and conjugating penetratin at each end of the PEG arms as outspread tentacles. Among the MVPs, 8-valent penetratin (8VP) stably compacted nucleic acids into positively charged polyplexes smaller than 100 nm, promoting cellular uptake efficiency (approaching 100%) and transfection rate (over 75%). After being instilled into the conjunctival sac, 8VP enabled rapid (<10 min) and prolonged (>6 h) distribution of nucleic acids in the retina via a noncorneal pathway. In a retinoblastoma-bearing mice model, topical instillation of 8VP/siRNA efficiently inhibited the protein expression of intraocular tumor without toxicity. MVP is advantageous over the commercial transfection reagent in safety and efficiency, and therefore provides a promising vector for noninvasive intraocular gene delivery.

Preliminary Development of Solid Dispersion for an Insoluble Compound ZL006 by Miniaturized Hot Melt Extrusion

The purpose of this study was to develop a solid dispersion (SD) by miniaturized hot-melt extrusion (HME) for an insoluble molecule ZL006 which showed potency of increasing leukocytes. A preliminary formulation screening was conducted using solvent evaporation method. The selected SD formulation was further optimized and scaled up using a miniaturized twin-screw extruder. Solid-state characterizations of the scale-up SD and its corresponding physical mixture (PM) were performed by X-ray powder diffraction (XRPD), modulated differential scanning calorimetry (mDSC), and Fourier's transform infrared spectroscopy (FTIR). XRPD and mDSC results indicated the formation of amorphous SD. FTIR spectrum indicated the possible hydrogen bond formation between the compound and the excipient. A discriminating non-sink condition micro-dissolution of SD showed the fast release of ZL006 which was approximately two-fold and three-fold of dissolution of PM and pure crystalline compound, respectively. The preliminary in vivo pharmacokinetics (PK) study in rats showed 71% oral bioavailability from the SD, while the bioavailability of ZL006 conventional suspension was less than 1%. Thus, an SD formulation for ZL006 with improved solubility and bioavailability was developed by miniaturized HME with minimal amount of compound at early preclinical stage, which could enable the preclinical evaluation.

Co-delivery of paclitaxel and melittin by glycopeptide-modified lipodisks for synergistic anti-glioma therapy

Nanosized lipodisks with flat circular phospholipid bilayers surrounded by PEGylated edges have demonstrated promise in drug delivery. In the present work, a lipodisk-based paclitaxel and melittin co-delivery system functionalized with glycopeptide 9G-A7R (9G-A7R-Disk/PTX/melittin) was successfully constructed, in which melittin which was fully protected from proteolysis and hemolysis was effectively reduced. The ratio of paclitaxel to melittin in lipodisks could be accurately controlled through a film hydration-adsorption method. Paclitaxel combined with melittin showed synergism against U87 cells in vitro, and 9G-A7R-Disk/PTX/melittin demonstrated an enhanced anti-glioma effect in vivo, significantly prolonging the survival time of glioma-bearing mice. The results suggested a promising formulation for the co-delivery of paclitaxel/melittin and glioma-targeted therapy.

Ligand-Modified Cell Membrane Enables the Targeted Delivery of Drug Nanocrystals to Glioma

The safe and efficient delivery of chemotherapeutic agents remains critical to anticancer therapy. Herein, we report on a targeted drug delivery system based upon a modified cell membrane coating technique and drug nanocrystals (NCs). Specifically, red blood cell (RBC) membrane was modified with targeting peptides through a facile insertion method involving avidin-biotin interactions. The RBC membrane-coated drug NCs (RBC-NCs) exhibited high drug loading, long-term stability, excellent biocompatibility, and prolonged retention time, all of which make them suitable for effective drug delivery. When modified with the tumor-targeting peptide c(RGDyK), the resulting RGD-RBC-NCs showed superior tumor accumulation and therapeutic efficacy both in mice bearing a subcutaneous tumor as well as orthotropic glioma. RBC-NC therapeutics can be readily generalized to the delivery of various drugs and for the treatment of a wide range of cancers.

Predicative values of serum microRNA-22 and microRNA-126 levels for non-small cell lung cancer development and metastasis: a case-control study

Presented study aims to explore the predictive values of serum microRNA-22 (miR-22) and miR-126 levels for non-small cell lung cancer (NSCLC) development and metastasis.A total of 127 NSCLC patients who were admitted in the First People's Hospital of Yancheng City from May, 2013 to May, 2015 were selected as the case group, including 71 cases of adenocarcinoma and 56 cases of squamous cell carcinoma. There were 112 healthy individuals selected as the control group. The qRT-PCR was performed to testify the serum miR-22 and miR-126 levels. Logistic regression analysis was conducted to analyze independent factors influencing NSCLC metastasis and receiver operating characteristic (ROC) curve was drawn to analyze the sensitivity and specificity of serum miR-22 and miR-126 levels in predicting NSCLC developments and metastasis.The serum miR-22 level was significantly higher in the case group than that in the control group, while the serum miR-126 level was lower in the case group as compared with that in the control group. Compared with squamous cell carcinoma patients, serum miR-22 level significantly increased, while serum miR-126 level decreased in patients with adenocarcinoma. Patients at III + IV stage showed increased serum miR-22 level and relatively decreased serum miR-126 level as compared to patients at I + II stage. Serum miR-22 level elevated in patients with metastasis; in contrast serum miR-126 level reduced in comparison to those without metastasis. In patients with familial inheritance, serum miR-22 level increased but serum miR-126 level decreased as compared to those without familial inheritance. The specificity and sensitivity of serum miR-22 and miR-126 levels in predicting NSCLC development were 99.11%, 84.30%, 82.68% and 96.40%, respectively. The specificity and sensitivity of serum miR-22 and miR-126 levels in predicting NSCLC metastasis were 59.74%, 96.00%, 84.00% and 62.30%, respectively.Results indicated that serum miR-22 and miR-126 levels may be used as the predicative biomarkers for NSCLC development and metastasis.

A Dual-Bioresponsive Drug-Delivery Depot for Combination of Epigenetic Modulation and Immune Checkpoint Blockade

Patients with advanced melanoma that is of low tumor-associated antigen (TAA) expression often respond poorly to PD-1/PD-L1 blockade therapy. Epigenetic modulators, such as hypomethylation agents (HMAs), can enhance the antitumor immune response by inducing TAA expression. Here, a dual bioresponsive gel depot that can respond to the acidic pH and reactive oxygen species (ROS) within the tumor microenvironment (TME) for codelivery of anti-PD1 antibody (aPD1) and Zebularine (Zeb), an HMA, is engineered. aPD1 is first loaded into pH-sensitive calcium carbonate nanoparticles (CaCO₃ NPs), which are then encapsulated in the ROS-responsive hydrogel together with Zeb (Zeb-aPD1-NPs-Gel). It is demonstrated that this combination therapy increases the immunogenicity of cancer cells, and also plays roles in reversing immunosuppressive TME, which contributes to inhibiting the tumor growth and prolonging the survival time of B16F10-melanoma-bearing mice.

Strategies of Combination Drug Delivery for Immune Checkpoint Blockades

The past few years have witnessed vast clinical accomplishments of immune checkpoint blockades (ICB), which block the regulatory receptor expressed on immune cells or tumor cells to prevent the suppression of antitumor cytotoxic T-cell responses. Despite this, limitations still exist, such as low objective response rate (ORR) and the risk of immune-related side effects. To address these issues, combination treatment strategies are vastly explored and recommended. This review summarizes recent advances in combination of ICB with therapies that participate in different stages of cancer immune cycle, including tumor antigen release, tumor antigen presentation, T-cell activation, recognition of cancer cells by T-cells, and tumor-killing activity. Challenges and potential opportunities of combination approaches in this field are also discussed.

Short Peptide-Mediated Brain-Targeted Drug Delivery with Enhanced Immunocompatibility

Peptide ligands have been exploited as versatile tools to facilitate targeted delivery of nanocarriers. However, the effects of peptide ligands on immunocompatibility and therapeutic efficacy of liposomes remain intricate. Here, a short and stable brain targeted peptide ligand D8 was modified on the surface of doxorubicin-loaded liposomes (D8-sLip/DOX), demonstrating prolonged blood circulation and lower liver distribution in comparison to the long and stable D-peptide ligand ^DCDX-modified doxorubicin-loaded liposomes (^DCDX-sLip/DOX) by mitigating natural IgM absorption. Despite the improved pharmacokinetic profiles, D8-sLip/DOX exhibited comparable brain targeting capacity in ICR mice and antiglioblastoma efficacy to ^DCDX-sLip/DOX in nude mice bearing intracranial glioblastoma. However, dramatic accumulation of ^DCDX-sLip/DOX in liver (especially during the first 8 h after intravenous injection) resulted in pathological symptoms, including nuclei swelling, necrosis of liver cells, and inflammation. These results suggest that short peptide ligand-mediated brain-targeted drug delivery systems possessing enhanced immunocompatibility are promising to facilitate efficient brain transport with improved biosafety.

Conjugation of haematopoietic stem cells and platelets decorated with anti-PD-1 antibodies augments anti-leukaemia efficacy

Patients with acute myeloid leukaemia who relapse following therapy have few treatment options and face poor outcomes. Immune checkpoint inhibition, for example, by antibody-mediated programmed death-1 (PD-1) blockade, is a potent therapeutic modality that improves treatment outcomes in acute myeloid leukaemia. Here, we show that systemically delivered blood platelets decorated with anti-PD-1 antibodies (aPD-1) and conjugated to haematopoietic stem cells (HSCs) suppress the growth and recurrence of leukaemia in mice. Following intravenous injection into mice bearing leukaemia cells, the HSC-platelet-aPD-1 conjugate migrated to the bone marrow and locally released aPD-1, significantly enhancing anti-leukaemia immune responses, and increasing the number of active T cells, production of cytokines and chemokines, and survival time of the mice. This cellular conjugate also promoted resistance to re-challenge with leukaemia cells. Taking advantage of the homing capability of HSCs and in situ activation of platelets for the enhanced delivery of a checkpoint inhibitor, this cellular combination-mediated drug delivery strategy can significantly augment the therapeutic efficacy of checkpoint blockade.

Efficacy of inverso isomer of CendR peptide on tumor tissue penetration

The dense extracellular matrix and high interstitial fluid pressure of tumor tissues prevent the ability of anti-tumor agents to penetrate deep into the tumor parenchyma for treatment effects. C-end rule (CendR) peptides can enhance the permeability of tumor blood vessels and tumor tissues via binding to neuropilin-1 (NRP-1), thus aiding in drug delivery. In this study, we selected one of the CendR peptides (sequence RGERPPR) as the parent l-peptide and substituted d-amino acids for the l-amino acids to synthesize its inverso peptide _D(RGERPPR). We investigated the NRP-1 binding activity and tumor-penetrating ability of _D(RGERPPR). We found that the binding affinity of _D(RGERPPR) with NRP-1 and the cellular uptake was significantly higher than that of RGERPPR. Evans Blue tests revealed that _D(RGERPPR) exhibited improved tumor-penetrating ability in C6, U87 and A549 tumor-bearing nude mice. Using nude mice bearing A549 xenograft tumors as a model, we found that the rate of tumor growth in the group co-administered with _D(RGERPPR) and gemcitabine (Gem) was significantly lower than the gemcitabine-treated group with a tumor suppression rate (TSR%) of 55.4%. Together, our results demonstrate that _D(RGERPPR) is a potential tumor-penetrating peptide.