Nanomedicine integrating the lipidic derivative of 5-fluorouracil,miriplatin and PD-L1 si RNA for enhancing tumor therapy

Immunosuppressive microenvironments present critical problems in clinical chemotherapy.To regulate the tumor immune microenvironment for enhancing antitumor effect,a combination of immune checkpoint inhibitors(ICIs)with chemotherapeutics has been applied clinically.In this study,miriplatin(MiPt),the lipidic derivative of 5-fluorouracil(Fu-OA),as well as the programmed death ligand 1(PD-L1)target si RNA(siPD-L1)were integrated into Lip-Pt/Fu@siPD-L1 nanoparticles(NPs)for chemo-immunotherapy.In vitro results showed that Lip-Pt/Fu@siPD-L1 NPs could exhibit effective siRNA gene silencing and promote the phagocytosis of tumor cells by macrophages.Furthermore,in vivo results revealed that LipPt/Fu@siPD-L1 NPs showed significantly higher anti-tumor efficiency than that of the physical mixing of Mi Pt,5-fluorouracil,and Lip@siPD-L1 NPs(delivery of siPD-L1 by liposomes).The best anti-tumor efficiency of Lip-Pt/Fu@siPD-L1 NPs resulted from the synergistic immunotherapeutic effects of Mi Pt and siPD-L1 based on the inhibition of CD47 expression and the downregulation of PD-L1 in tumor cells,which elicited a robust anti-tumor immune response through the activation of macrophage phagocytosis and immune checkpoint inhibition.The Lip-Pt/Fu@siPD-L1 NPs provide a potential strategy for tumor chemo-immunotherapy.

Antitumor synergism between PAK4 silencing and immunogenic phototherapy of engineered extracellular vesicles

Immunotherapy has revolutionized the landscape of cancer treatment.However,single immunotherapy only works well in a small subset of patients.Combined immunotherapy with antitumor synergism holds considerable potential to boost the therapeutic outcome.Nevertheless,the synergistic,additive or antagonistic antitumor effects of combined immunotherapies have been rarely explored.Herein,we established a novel combined cancer treatment modality by synergizing p21-activated kinase 4(PAK4)silencing with immunogenic phototherapy in engineered extracellular vesicles(EVs)that were fabricated by coating M1 macrophage-derived EVs on the surface of the nano-complex cores assembled with si RNA against PAK4 and a photoactivatable polyethyleneimine.The engineered EVs induced potent PAK4 silencing and robust immunogenic phototherapy,thus contributing to effective antitumor effects in vitro and in vivo.Moreover,the antitumor synergism of the combined treatment was quantitatively determined by the Compu Syn method.The combination index(CI)and isobologram results confirmed that there was an antitumor synergism for the combined treatment.Furthermore,the dose reduction index(DRI)showed favorable dose reduction,revealing lower toxicity and higher biocompatibility of the engineered EVs.Collectively,the study presents a synergistically potentiated cancer treatment modality by combining PAK4 silencing with immunogenic phototherapy in engineered EVs,which is promising for boosting the therapeutic outcome of cancer immunotherapy.

Improved method for synthesis of low molecular weight protamine–siRNA conjugate

RNAi technology has aroused wide public interest due to its high efficiency and specificity to treat multiple types of diseases. However, the effective delivery of siRNA remains a challenge due to its large molecular weight and strong anionic charge. Considering their remarkable functions in vivo and features that are often desired in drug delivery carriers, biomimetic systems for siRNA delivery become an effective and promising strategy. Based on this, covalent attachment of synthetic cell penetrating peptides(CPP) to siRNA has become of great interest. We developed a monomeric covalent conjugate of low molecular weight protamine(LMWP, a well-established CPP) and siRNA via a cytosol-cleavable disulfide linkage using PEG as a crosslinker. Results showed that the conjugates didn't generate coagulation, and exhibited much better RNAi potency and intracellular delivery compared with the conventional charge-complexed CPP/siRNA aggregates. Three different synthetic and purification methods were compared in order to optimize synthesis efficiency and product yield. The methodology using hetero-bifunctional NHS–PEG–OPSS as a crosslinker to synthesize LMWP–siRNA simplified the synthesis and purification process and produced the highest yield. These results pave the way towards siRNA biomimetic delivery and future clinical translation.

Biosafety materials:Ushering in a new era of infectious disease diagnosis and treatment with the CRISPR/Cas system

Despite multiple virus outbreaks over the past decade,including the devastating coronavirus disease 2019(COVID-19)pandemic,the lack of accurate and timely diagnosis and treatment technologies has wreaked havoc on global biosecurity.The clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated proteins(Cas)system has the potential to address these critical needs for tackling infectious diseases to detect viral nucleic acids and inhibit viral replication.This review summarizes how the CRISPR/Cas system is being utilized for the treatment and diagnosis of infectious diseases with the help of biosafety materials and highlights the design principle and in vivo and in vitro efficacy of advanced biosafety materials used to deal with virus attacks.

Ultrasound-mediated targeted microbubbles： a new vehicle for cancer therapy

With the hope of overcoming the serious side effects, great endeavor has been made in tumor-targeted chemotherapy, and various drug delivery modalities and drug carriers have been made to decrease systemic toxicity caused by chemotherapeutic agents. Scientists from home and abroad focus on the research of targeted microbubbles contrast agent, and the use of the targeted ultrasound microbubble contrast agent can carry gene drugs and so on to the target tissue, as well as mediated tumor cell apoptosis and tumor microvascular thrombosis block, etc., thus plays the role of targeted therapy. Recent studies have elucidated the mechanisms of drug release and absorption, however, much work remains to be done in order to develop a successful and optimal system. In this review, we summarized the continuing efforts in under-standing the usage of the ultrasound triggered target microbubbles in cancer therapy, from release mechanism to preparation methods. The latest applications of ultra-sound-triggered targeted microbubbles in cancer therapy, especially in gene therapy and antiangiogenic cancer therapy were discussed. Moreover, we concluded that as a new technology, ultrasound-triggered targeted microbubbles used as drug carriers and imaging agents are still energetic and are very likely to be translated into clinic in the near future.

Curcumin based combination therapy for anti-breast cancer： from in vitro drug screening to in vivo efficacy evaluation

While drug resistance appears to be an inevitable problem of an increasing number of anticancer drugs in monotherapy, combination drug therapy has become a prosperous method to reduce the administered total drug dosages as well as overcome the drug resistance of carcinoma cells. Curcumin, considered to possess multi- faceted roles in cancer treatment according to its multiple anti-neoplastic mechanisms as a depressor of chemo- resistance, can significantly facilitate its anti-cancer functions and improve therapeutic effects via combination usage with a variety of other drugs with different reaction mechanisms. To explore this possibility, four anti-cancer chemotherapeutic agents that all possess a certain degree of drug resistance problems, including three tyrosine kinase inhibitors （erlotinib, sunitinib and sorafenib） that are acting on different cell pathways and a typical anticancer drug doxorubicin, were combined with curcumin individually to examine the synergistic anti-tumor effect both in vitro and in vivo. Results revealed that sunitinib combined with curcumin at the molar ratio of 0.46 yielded the most potent synergistic effect in vitro, and was therefore chosen for further animal evaluation. To further enhance the anti- cancer effect, bovine serum albumin （BSA） nanoparticles were utilized as a carrier to deliver the selected drug combination in situ. Preliminary in vivo findings confirmed our hypothesis of being able to maintain a similar injected drug ratio for prolonged time periods in tested animals by our approach, thereby maximizing the therapeutic potency yet minimizing the toxicity of these drugs. This work could open up a new avenue on combination drug therapy and realization the clinical utility of such drugs.

Developing macromolecular therapeutics:the future drug-of-choice

Macromolecular drugs including peptides,proteins,antibodies,polysaccharides and nucleic acids have been widely used for therapy of major diseases such as carcinoma and AIDS as well as cardiovascular and neurodegenerative disorders among other medical conditions.Due to their unmatched properties of high selectivity and efficiency,macromolecular drugs have been recognized as the drug-of-choice of the future.Since worldwide progress on macromolecular therapeutics still remains in the infant stage and is therefore wide open for equalground competition,R&D related to macromolecular drugs should be considered as the main point of focus in China in setting up its strategic plans in pharmaceutical development.In this article,research strategies and drug delivery approaches that should be adopted to enhance the therapeutic effects of macromolecular drugs are reviewed.In addition,comments concerning how to implement such strategies to excel from competition in this challenging research field,such as the design of innovative and highly effective delivery systems of macromolecular drugs with self-owned intellectual property rights,are provided.

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

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

Tat-functionalized Ag-Fe_3O_4 nano-composites as tissue-penetrating vehicles for tumor magnetic targeting and drug delivery

In this paper, we prepared a dual functional system based on dextrin-coated silver nanoparticles which were further attached with iron oxide nanoparticles and cell penetrating peptide(Tat), producing Tat-modified Ag-Fe_3O_4 nanocomposites(Tat-FeAgNPs). To load drugs, an –SH containing linker, 3-mercaptopropanohydrazide, was designed and synthesized. It enabled the silver carriers to load and release doxorubicin(Dox) in a pH-sensitive pattern. The delivery efficiency of this system was assessed in vitro using MCF-7 cells, and in vivo using null BalB/c mice bearing MCF-7 xenograft tumors. Our results demonstrated that both Tat and externally applied magnetic field could promote cellular uptake and consequently the cytotoxicity of doxorubicin-loaded nanoparticles,with the IC_(50) of Tat-FeAgNP-Dox to be 0.63 mmol/L. The in vivo delivery efficiency of Tat-FeAgNP carrying Cy5 to the mouse tumor was analyzed using the in vivo optical imaging tests, in which TatFeAgNP-Cy5 yielded the most efficient accumulation in the tumor(6.772.4% ID of Tat-FeAgNPs).Anti-tumor assessment also demonstrated that Tat-FeAgNP-Dox displayed the most significant tumor-inhibiting effects and reduced the specific growth rate of tumor by 29.6%(P ? 0.009), which could be attributed to its superior performance in tumor drug delivery in comparison with the control nanovehicles.

Nose-to-brain delivery of macromolecules mediated by cell-penetrating peptides

Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood brain bather (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to circumventing the BBB and has already been intensively investigated for brain delivery of small drugs, new challenges arise for intranasal delivery of proteins because of their larger size and hydrophilicity. h order to overcome the bathers and take advantage of available pathways (e.g., epithelial tight junctions, uptake by olfactory neurons, transport into brain tissues, and intra-brain diffusion), a low molecular weight protamine (LMWP) cell-penetrating peptide was utilized to facilitate nose-to-brain transport. Cell-penetrating peptides (CPP) have been widely used to mediate macromolecular delivery through many kinds of biobarriers. Our results show that conjugates of LMWP proteinsare able to effectively penetrate into the brain after intranasal administration. The CPP-based intranasal method highlights a promising solution for protein therapy of brain diseases. (C) 2016 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.

Overcoming oral insulin delivery barriers： application of cell penetrating peptide and silica-based nanoporous composites

Oral insulin delivery has received the most attention in insulin formulations due to its high patient compliance and, more importantly, to its potential to mimic the physiologic insulin secretion seen in non-diabetic individuals. However, oral insulin delivery has two major limitations： the enzymatic barrier that leads to rapid insulin degradation, and the mucosal barrier that limits insulin＇s bioavailability. Several approaches have been actively pursued to circumvent the enzyme barrier, with some of them receiving promising results. Yet, thus far there has been no major success in overcoming the mucosal barrier, which is the main cause in undercutting insulin＇s oral bioavailability. In this review of our group＇s research, an innovative silica-based, mucoadhesive oral insulin formulation with encapsulated-insulin/cell penetrating peptide （CPP） to overcome both enzyme and mucosal barriers is discussed, and the preliminary and convincing results to confirm the plausibility of this oral insulin delivery system are reviewed. In vitro studies demonstrated that the CPPinsulin conjugates could facilitate cellular uptake of insulin while keeping insulin＇s biologic functions intact. It was also confirmed that low molecular weight protamine （LMWP） behaves like a CPP peptide, with a cell translocation potency equivalent to that of the widely studied TAT. The mucoadhesive properties of the produced silica-chitosan composites could be controlled by varying both the pH and composition; the composite consisting of chitosan （25wt-%） and silica （75 wt-%） exhibited the greatest mucoadhesion at gastric pH. Furthermore, drugrelease from the composite network could also be regulated by altering the chitosan content. Overall, the universal applicability of those technologies could lead to development of a generic platform for oral delivery of many other bioactive compounds, especially for peptide or protein drugs which inevitably encounter the poor bioavailability issues.

Long acting carmustine loaded natural extracellular matrix hydrogel for inhibition of glioblastoma recurrence after tumor resection

Many scientific efforts have been made to penetrate the blood-brain barrier and target glioblastoma cells,but the outcomes have been limited.More attention should be given to local inhibition of recurrence after glioblastoma resection to meet real medical needs.A biodegradable wafer containing the chemotherapeutics carmustine(1,3-bis(2-chloroethyl)-1-nitrosourea,BCNU)was the only local drug delivery system approved for clinical glioblastoma treatment,but with a prolonged survival time of only two months and frequent side effects.In this study,to improve the sustained release and prolonged therapeutic effect of drugs for inhibiting tumor recurrence after tumor resection,both free BCNU and BCNU-poly(lactic-co-glycolic acid)(the ratio of lactic acid groups to glycolic acid groups is 75/25)nanoparticles were simultaneously loaded into natural extracellular matrix hydrogel from pigskin to prepare BCNU gels.The hydrogel was injected into the resection cavity of a glioblastoma tumor immediately after tumor removal in a fully characterized resection rat model.Free drugs were released instantly to kill the residual tumor cells,while drugs in nanoparticles were continuously released to achieve a continuous and effective inhibition of the residual tumor cells for 30 days.These combined actions effectively restricted tumor growth in rats.Thus,this strategy of local drug implantation and delivery may provide a reliable method to inhibit the recurrence of glioblastoma after tumor resection in vivo.

Significance and strategies in developing delivery systems for bio-macromolecular drugs

Successful development of a new drug is prohibitively expensive, and is estimated to cost approxi- mately S100-500 million US dollars for a single clinical drug. Yet, a newly developed drug can only enjoy its patent protection for 18 years, meaning that after this protected time period, any company can manufacture this product and thus the profit generated by this drug entity would reduce dramatically. Most critically, once a drug is being synthesized, its physical, chemical, and biological attri- butes such as bioavailability and in vivo pharmacokinetics are all completely fixed and cannot be changed. In principal and practice, only the application of an appro- priately designed drug delivery system （DDS） is able to overcome such limitations, and yet the cost of developing a novel drug delivery system is less than 10% of that of developing a new drug. Because of these reasons, the new trend in pharmaceutical development has already begun to shift from the single direction of developing new drugs in the past to a combined mode of developing both new drugs and innovative drug delivery systems in this century. Hence, for developing countries with relatively limited financial resources, a smart strategic move would be to focus on the development of new DDS, which has a significantly higher benefit/risk ratio when comparing to the development of a new drug. Because of the unmatched reaction efficiency and a repetitive action mode, the therapeutic activity of a single bio-macromolecular drug （e.g., protein toxins, gene products, etc.） is equivalent to about 10^6- 10^8 of that from a conventional small molecule anti-cancer agent （e.g., doxorubicin）. Hence, bio-macromolecular drugs have been recognized around the world as the future ＂drug-of-choice＂. Yet, among the 〉 10000 drugs that are currently available, only -150 of them belong to these bio- macromolecular drugs （an exceedingly low 1.2%）, reflect- ing the difficulties of utilizing these agents in clinical practice. In general, the bottleneck limitations of these bio- macromolecular drugs are two-fold： （1） the absence of a preferential action of the drug on tumor cells as opposed to normal tissues, and （2） the lack of ability to cross the tumor cell membrane. In this review, we provide strategies of how to solve these problems simultaneously and collec- tively via the development of innovative drug delivery systems. Since worldwide progress on bio-macromolecular therapeutics still remains in the infant stage and thus open for an equal-ground competition, we wish that this review would echo the desire to industrialized countries such as China to set up its strategic plan on developing delivery systems for these bio-macromolecular drugs, thereby realizing their clinical potential.

Immobilization of penicillin G acylase onto amino-modified silica hydrogel

Amino-modified silica hydrogel(N-MSHG)was prepared by a simple sol-gel processing via the cocondensation of commercial silica sol with 3-aminopropyltrieoxysilane.Penicillin G acylase(PGA),a model enzyme,was covalently immobilized onto the N-MSHG and then was used for the enzymatic synthesis of amoxicillin.The samples were characterized by Nitrogen sorption analysis,FT-IR and thermal gravimetric analysis(TGA).The results showed that the amino-modified gel was a mesoporous material with an average pore size of 12.64±0.17 nm.The immobilization process was efficient and the immobilized enzyme showed high catalytic efficiency.The yield of the synthesis of amoxicillin in aqueous media was 38%for 2.5 h.This sol-gel preparation is simple and shows prominent potential value in industrial processing.