The Recent Advance of Cell-Penetrating and Tumor-Targeting Peptides as Drug Delivery Systems Based on Tumor Microenvironment.

Cancer has become the primary reason for industrial countries death. Although first-line treatments have achieved remarkable results in inhibiting tumors, they could have serious side effects because of insufficient selectivity. Therefore, specific localization of tumor cells is currently the main desire for cancer treatment. In recent years, cell-penetrating peptides (CPPs), as a kind of promising delivery vehicle, have attracted much attention because they mediate the high-efficiency import of large quantities of cargos in vivo and vitro. Unfortunately, the poor targeting of CPPs is still a barrier to their clinical application. In order to solve this problem, researchers use the various characteristics of tumor microenvironment and multiple receptors to improve the specificity toward tumors. This review focuses on the characteristics of the tumor microenvironment, and introduces the development of strategies and peptides based on these characteristics as drug delivery system in the tumor-targeted therapy.

Discovery of novel PROTACs based on multi-targeted angiogenesis inhibitors.

Anti-angiogenesis has been proved to be an effective strategy for the treatment of tumors. Anti-angiogenic drugs had achieved certain therapeutic effects. However, drug resistance also gradually emerged and limited the application of angiogenesis inhibitors. Proteolysis Targeting Chimeras (PROTACs) are bifunctional molecules capable of degrading proteins through the ubiquitin-proteasome system (UPS). Compared with traditional inhibitors, they displayed advantages of less dosage, lower toxicity and less resistance. In this study, we designed and synthesized a series of novel PROTACs based on our recently reported multi-targeted angiogenesis inhibitor S5. Preliminary biological evaluation of title PROTACs was carried out in various cell lines. The results indicated that these novel bifunctional PROTACs displayed potential in degrading BRAF protein. Their degradation mechanism showed that the degradation of BRAF by PROTAC-1 was dependent on binding to target proteins and E3 ubiquitin ligase. Our findings provided further evidence that these novel PROTACs could be considered in further application in overcome of clinical resistance of traditional angiogenesis inhibitors.

Discovery of selective platelet-derived growth factor receptor-beta (PDGFR-ß) bifunctional small-molecule degraders.

Proteolysis-targeting chimeras (PROTACs) is a promising strategy for treatment of various diseases by degrading of disease-related proteins in recent years. Up to now, most PROTAC molecules are mainly aimed at the degradation of intracellular proteins, but many disease-related proteins are membrane or extracellular proteins. The targeted degradation of membrane proteins would be an attractive and general strategy for discovery of novel PROTACs. Herein, we report the development of multi-targeted kinase inhibitor sorafenib-based PROTACs, they can selectively degrade platelet-derived growth factor receptor beta (PDGFR-ß). We provide a method that can be used to degrade cell membrane proteins. To our knowledge, this study also is the first report of PROTAC induced PDGFR-ß degradation in cancer cells.

Identification of a Putative SARS-CoV-2 Main Protease Inhibitor through In Silico Screening of Self-Designed Molecular Library.

There have been outbreaks of SARS-CoV-2 around the world for over three years, and its variants continue to evolve. This has become a major global health threat. The main protease (Mpro, also called 3CLpro) plays a key role in viral replication and proliferation, making it an attractive drug target. Here, we have identified a novel potential inhibitor of Mpro, by applying the virtual screening of hundreds of nilotinib-structure-like compounds that we designed and synthesized. The screened compounds were assessed using SP docking, XP docking, MM-GBSA analysis, IFD docking, MD simulation, ADME/T prediction, and then an enzymatic assay in vitro. We finally identified the compound V291 as a potential SARS-CoV-2 Mpro inhibitor, with a high docking affinity and enzyme inhibitory activity. Moreover, the docking results indicate that His41 is a favorable amino acid for pi-pi interactions, while Glu166 can participate in salt-bridge formation with the protonated primary or secondary amines in the screened molecules. Thus, the compounds reported here are capable of engaging the key amino acids His41 and Glu166 in ligand-receptor interactions. A pharmacophore analysis further validates this assertion.

Design, synthesis, and biological evaluation of novel Bcr-AblT315I inhibitors incorporating amino acids as flexible linker.

Despite the success of imatinib in CML therapy through Bcr-Abl inhibition, acquired drug resistance occurs over time in patients. In particular, the resistance caused by T315I mutation remains a challenge in clinic. Herein, we embarked on a structural optimization campaign aiming at discovery of novel Bcr-Abl inhibitors toward T315I mutant based on previously reported dibenzoylpiperazin derivatives. We proposed that incorporation of flexible linker could achieve potent inhibition of Bcr-AblT315I by avoiding steric clash with bulky sidechain of Ile315. A library of 28 compounds with amino acids as linker has been developed and evaluated. Among them, compound AA2 displayed the most potent activity against Bcr-AblWT and Bcr-AblT315I, as well as toward Bcr-Abl driven K562 and K562R cells. Further investigations indicated that AA2 could induce apoptosis of K562 cells and down regulate phosphorylation of Bcr-Abl. In summary, the compounds with amino acid as novel flexible linker exhibited certain antitumor activities, providing valuable hints for the discovery of novel Bcr-Abl inhibitors to overcome T315I mutant resistance, and AA2 could be considered as a candidate for further optimization.

Tetrahedral Framework Nucleic Acids Promote Corneal Epithelial Wound Healing in Vitro and in Vivo.

Poor post-traumatic wound healing can affect the normal function of damaged tissues and organs. For example, poor healing of corneal epithelial injuries may lead to permanent visual impairment. It is of great importance to find a therapeutic way to promote wound closure. Tetrahedral framework nucleic acids (tFNAs) are new promising nanomaterials, which can affect the biological behavior of cells. In the experiment, corneal wound healing is used as an example to explore the effect of tFNAs on wound healing. Results show that the proliferation and migration of human corneal epithelial cells are enhanced by exposure to tFNAs in vitro, possibly relevant to the activation of P38 and ERK1/2 signaling pathway. An animal model of corneal alkali burn is established to further identify the facilitation effect of tFNAs on corneal wound healing in vivo. Clinical evaluations and histological analyses show that tFNAs can improve the corneal transparency and accelerate the re-epithelialization of wounds. Both in vitro and in vivo experiments show that tFNAs can play a positive role in corneal epithelial wound healing.

Effect of tetrahedral DNA nanostructures on proliferation and osteo/odontogenic differentiation of dental pulp stem cells via activation of the notch signaling pathway.

Dental pulp stem cells (DPSCs) derived from the human dental pulp tissue have multiple differentiation capabilities, such as osteo/odontogenic differentiation. Therefore, DPSCs are deemed as ideal stem cell sources for tissue regeneration. As new nanomaterials based on DNA, tetrahedral DNA nanostructures (TDNs) have tremendous potential for biomedical applications. Here, the authors aimed to explore the part played by TDNs in proliferation and osteo/odontogenic differentiation of DPSCs, and attempted to investigate if these cellular responses could be driven by activating the canonical Notch signaling pathway. Upon exposure to TDNs, proliferation and osteo/odontogenic differentiation of DPSCs were dramatically enhanced, accompanied by up regulation of Notch signaling. In general, our study suggested that TDNs can significantly promote proliferation and osteo/odontogenic differentiation of DPSCs, and this remarkable discovery can be applied in tissue engineering and regenerative medicine to develop a significant and novel method for bone and dental tissue regeneration.

[Adhesion of Streptococcus mutans to removable denture crowns].

OBJECTIVE: To determine adhesion of Streptococcus mutans (S. mutans) to different kinds of removable denture crowns for the purpose of minimizing influence of removable denture on oral environment. METHODS: Three kinds of removable denture crowns (single color synthetic resin teeth, alloy pin porcelain tooth and minute color synthetic resin teeth) were adsorbed S. mutans for 24 h in sterile saliva, The adhered bacteria were counted by means of sonic oscillation and bacteria coating. RESULTS: Highest level of adhesion was found on ,the single color synthetic resin teeth was adsorbed mostly, followed by alloy pin porcelain teeth. Minute color synthetic resin teeth had far less adhesion than the others (P<0.01). CONCLUSION: Minute color synthetic resin teeth have less adhesion of S. mutans, which may be associated with their lower level of surface free energy.

Comparing Bone Alteration and Esthetic Recovery Between the Socket-Shield Technique and the Conventional Immediate Implant Technique: A Retrospective Study.

PURPOSE: To evaluate bone preservation and esthetic recovery between the socket-shield technique (SST) with different labial bone plate thicknesses and the conventional immediate implant technique (CIIT). MATERIALS AND METHODS: Patients who underwent immediate implant placement in the anterior region were divided into three groups: the SST with a thickwall phenotype (> 1 mm; SSTA group), the SST with a thin-wall phenotype (< 1 mm; SSTB group), and the CIIT with a thickwall phenotype (> 1 mm; CIIT group). Radiologic images and clinical photos were collected before surgery, immediately postoperatively, and 6 months postoperatively. The labial bone width, labial bone width change (BWC), labial bone volume change (BVC), pink esthetic score (PES), and complication rate were evaluated among the three groups. Statistical analysis was performed using SPSS software. RESULTS: A total of 60 patients (n = 20/group) were enrolled in this 6-month retrospective study. The BWC in the SSTA group (0.22 to 0.30 mm) and the SSTB group (0.18 to 0.33 mm) was less than that in the CIIT group (0.61 to 0.80 mm; P < .004). The SSTA group and the SSTB group had a lower BVC (24.08 vs 21.14 vs 54.81, respectively; P = .004) and greater PES (11.75 vs 11.65 vs 10.65, respectively; P = .009) than the CIIT group. No complications occurred among these patients. CONCLUSIONS: With the limitations of this study, it can be concluded that the SST is a reliable method for preserving bone and achieving satisfactory esthetic outcomes. The labial bone plate phenotype associated with the SST has minimal impact on both clinical and radiologic outcomes.

Inside-out extracellular vesicles-like biomimetic magnetic nanoparticles for efficient screening P-Glycoprotein inhibitors to overcome cancer multidrug resistance.

The discovery of P-Glycoprotein (P-gp) inhibitors to block chemotherapy drugs efflux is considered an attractive treatment strategy for overcoming cancer multidrug resistance (MDR). Cell membrane biomimetic platform has emerged as a promising candidate method for screening small molecule P-gp inhibitors from natural products. However, randomly oriented cell membrane coating does not guarantee the inward-opening conformation of P-gp, limiting the precise screening of P-gp inhibitors. Herein, inside-out orientation extracellular vesicles camouflaged magnetic nanoparticles (IOVMNPs) were prepared to discover P-gp inhibitors with low toxicity and high efficiency from natural products. The orientation of extracellular vesicles on the surface of IOVMNPs was rigorously confirmed by immunogold electron microscopy and sialic acid quantification assay. Finally, two potential P-gp inhibitors, honokiol and magnolol, were captured by obtained IOVMNPs. The effect of MDR reversal in combination with chemotherapy drugs was further verified by pharmacological activity experiments. The inside-out orientation extracellular vesicles encapsulation strategy provides an effective tool for the discovery of novel P-gp inhibitors from nature products, thus further extending the application field of orientation assembly cell membrane biomimetic magnetic nanoparticles. This inside-out extracellular vesicles coating also proposes a new concept for the assembly of cell membrane biomimetic platform.

The nano-windmill exerts superior anti-inflammatory effects via reducing choline uptake to inhibit macrophage activation.

Macrophages' activation plays a central role during the development and progression of inflammation, while the regulation of metabolic reprogramming of macrophages has been recently identified as a novel strategy for anti-inflammatory therapies. Our previous studies have found that tetrahedral framework nucleic acid (tFNA) plays a mild anti-inflammatory effect by inhibiting macrophage activation, but the specific mechanism remains unclear. Here, by metabolomics and RNA sequencing, choline uptake is identified to be significantly repressed by decreased slc44a1 expression in tFNA-treated activated macrophages. Inspired by this result, combined with the excellent delivery capacities of tFNA, siR-slc44a1 is loaded into the tFNA to develop a new tFNA-based small interfering RNA (siRNA) delivery system named 'nano-windmill,' which exhibits a synergetic role by targeting slc44a1, finally blowing up the anti-inflammatory effects of tFNA to inhibit macrophages activation via reducing choline uptake. By confirming its anti-inflammatory effects in chronic (periodontitis) and acute (sepsis) inflammatory disease, the tFNA-based nanomedicine developed for inflammatory diseases may provide broad prospects for tFNA upgrading and various biological applications such as anti-inflammatory.

Hypoxia Drives Material-Induced Heterotopic Bone Formation by Enhancing Osteoclastogenesis via M2/Lipid-Loaded Macrophage Axis.

Heterotopic ossification (HO) is a double-edged sword. Pathological HO presents as an undesired clinical complication, whereas controlled heterotopic bone formation by synthetic osteoinductive materials shows promising therapeutic potentials for bone regeneration. However, the mechanism of material-induced heterotopic bone formation remains largely unknown. Early acquired HO being usually accompanied by severe tissue hypoxia prompts the hypothesis that hypoxia caused by the implantation coordinates serial cellular events and ultimately induces heterotopic bone formation in osteoinductive materials. The data presented herein shows a link between hypoxia, macrophage polarization to M2, osteoclastogenesis, and material-induced bone formation. Hypoxia inducible factor-1α (HIF-1α), a crucial mediator of cellular responses to hypoxia, is highly expressed in an osteoinductive calcium phosphate ceramic (CaP) during the early phase of implantation, while pharmacological inhibition of HIF-1α significantly inhibits M2 macrophage, subsequent osteoclast, and material-induced bone formation. Similarly, in vitro, hypoxia enhances M2 macrophage and osteoclast formation. Osteoclast-conditioned medium enhances osteogenic differentiation of mesenchymal stem cells, such enhancement disappears with the presence of HIF-1α inhibitor. Furthermore, metabolomics analysis reveals that hypoxia enhances osteoclastogenesis via the axis of M2/lipid-loaded macrophages. The current findings shed new light on the mechanism of HO and favor the design of more potent osteoinductive materials for bone regeneration.

Design, synthesis, and biological evaluation of trizole-based heteroaromatic derivatives as Bcr-Abl kinase inhibitors.

Bcr-Abl is a key driver in the pathophysiology of CML. Broadening the chemical diversity of Bcr-Abl kinase inhibitors to overcome drug resistance is a current medical demand for CML treatment. As a continuation to our research, a series of compounds with heteroaromatics-trizole scaffold as hinge binding moiety (HBM) were developed as Bcr-Abl inhibitors based on in silico modeling analysis. Biological results indicated that these compounds exhibited a significantly enhanced inhibition against Bcr-AblWT and Bcr-AblT315I in kinases assays, along with improved anti-proliferative activities in leukemia cell assays, compared with previous disclosed compounds. In particular, compounds 9f, 28c, 31, and 44c displayed comparable even better potency with that of Imatinib in enzymatic assay and cell assays including K562 cells and adriamycin-resistant K562/A cells. Moreover, compounds 9f, 28c, and 44c exhibited potent inhibition activities against K562R cells bearing T315I mutant with IC50 of 13.35 µM, 40.14 µM, and 1.91 µM, respectively, outperforming that of Imatinib. Meanwhile, the inhibition of Bcr-Abl activity in Ba/F3 cells demonstrated that these compounds exerted effects mainly by acting on Bcr-Abl. Additionally, compounds 9f, 28c, and 44c effectively induced apoptosis, arrest the cell cycle at S or G2/M phase, and inhibited phosphorylation of Bcr-Abl and STAT5 in a dose-dependent manner. Docking studies indicated that trizole indeed retained the hydrophobic interaction of aromatic heterocycles with hinge region, and ADME prediction suggested that tested compounds had a favorable safety profile. Therefore, aromatic heterocycles incorporated with trizole could serve as a promising HBM for Bcr-Abl inhibitors with proline as fexibile linker, and compounds 9f, 28c, especially 44c could be served as a starting point for further optimization.

Dimensionality reduction of ultrasonic array data for characterization of inclined defects based on supervised locality preserving projection.

Ultrasonic arrays are increasingly used for inspection of the structural components in non-destructive testing (NDT) applications. The ultrasonic array data can be processed to form high-resolution images for detection and localization of defects. Alternatively, the scattering matrix can be extracted from the full matrix of array data and used for defect characterization if the defect size is small (i.e., comparable to an ultrasonic wavelength). This paper studies the dimensionality reduction problem of scattering matrix databases. In particular, we focus on accurate characterization of inclined defects for which previous approaches based on principal component analysis (PCA) yielded high characterization uncertainty. We propose a supervised approach based on locality preserving projection (LPP) and introduce noise constraints to the objective function of LPP. In simulation, the proposed approach is shown to produce a well-resolved defect manifold for 45°ellipses. Characterization results obtained using the simulated noisy measurements of four 60°ellipses confirm the performance improvement of LPP over PCA. In experiments, three 60°ellipses and two surface-breaking cracks have been characterized. On average, the root-mean-square (RMS) sizing error given by the LPP approach is 39.0% lower compared to PCA for the ellipses and 11.1% lower for the surface-breaking cracks.

The cGAS-STING Pathway in Bacterial Infection and Bacterial Immunity.

Cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) (cGAMP) synthase (cGAS), along with the adaptor stimulator of interferon genes (STING), are crucial components of the innate immune system, and their study has become a research hotspot in recent years. Many biochemical and structural studies that have collectively elucidated the mechanism of activation of the cGAS-STING pathway with atomic resolution have provided insights into the roles of the cGAS-STING pathway in innate immunity and clues to the origin and evolution of the modern cGAS-STING signaling pathway. The cGAS-STING pathway has been identified to protect the host against viral infection. After detecting viral dsDNA, cGAS synthesizes a second messenger to activate STING, eliciting antiviral immune responses by promoting the expression of interferons (IFNs) and hundreds of IFN-stimulated genes (ISGs). Recently, the cGAS-STING pathway has also been found to be involved in response to bacterial infections, including bacterial pneumonia, melioidosis, tuberculosis, and sepsis. However, compared with its functions in viral infection, the cGAS-STING signaling pathway in bacterial infection is more complex and diverse since the protective and detrimental effects of type I IFN (IFN-I) on the host depend on the bacterial species and infection mode. Besides, STING activation can also affect infection prognosis through other mechanisms in different bacterial infections, independent of the IFN-I response. Interestingly, the core protein components of the mammalian cGAS-STING signaling pathway have been found in the bacterial defense system, suggesting that this widespread signaling pathway may have originated in bacteria. Here, we review recent findings related to the structures of major molecules involved in the cGAS-STING pathway and the effects of the cGAS-STING pathway in various bacterial infections and bacterial immunity, which may pave the way for the development of new antibacterial drugs that specifically kill bacteria without harmful effects on the host.

The Application of Tetrahedral Framework Nucleic Acids as a Drug Carrier in Biomedicine Fields.

In recent years, tetrahedral Framework Nucleic Acids(tFNAs) have become a hot topic in the field of DNA nanostructures because of their stable structures, nanoscale size, superior mechanical properties and convenient synthesis with high yield. tFNAs are considered promising drug delivery carriers because they can pass through the cellular membrane without any help and they have a good biocompatibility and biodegradability. Besides, they have rich modification sites, they can be modified by kinds of functional groups. The functionalization molecules can be modified on the vertexes, embedded between the double-stranded DNA of the tetrahedron edges, hanged on the edges, or encapsulated in the cage-like structure of the tetrahedron. The structure of tetrahedron can also be intelligently controlled through smart design, such as integrating DNA hairpin loop structure onto the edges. Nowadays, DNA tetrahedron will have a broader development prospect in the application of drug transport carriers and intelligent drug carriers. Therefore, DNA material is a new carrier material with great advantages and has a very broad application prospect in the construction of an intelligent drug transport system.

Recent advances in, and challenges of, anti-angiogenesis agents for tumor chemotherapy based on vascular normalization.

A major problem associated with cancer treatment is resistance-prone chemotherapeutic drugs. An increasing number of studies have documented that the occurrence of resistance tends to be associated with abnormal blood vessels. In 2001, Jain proposed the vascular normalization theory, which was recently applied to the drug-resistant treatment of tumors in the clinic. Through the intervention of angiogenesis inhibitors, remodeling the structure and function of abnormal vessels can maximize the efficacy of chemotherapeutic drugs. In this review, we systematically describe the occurrence and progress of tumor angiogenesis, as well as the pathological characteristics of tumor blood vessels. Moreover, druggable targets for vascular normalization and the development of related inhibitors are also outlined.

Application of Nanomaterials in the Treatment and Diagnosis of Ophthalmology Diseases.

Eye diseases often lead to impaired vision and seriously affect the daily life of patients. Local administration of ophthalmic drugs is one of the most important approaches for the treatment of ophthalmic diseases. However, due to the special biochemical environment of the ocular tissue and the existence of many barriers, the bioavailability of conventional ophthalmic preparations in the eye is very low. Nanomaterials can be utilized as carriers of drugs, which can improve the absorption, distribution, metabolism and bioavailability of drugs in eyes. Nanomaterials have also the advantages of small size, simple preparation, good degradability, strong targeting, and little stimulation to biological tissues, providing an innovative and practical method for the drug delivery of ophthalmic diseases. In addition, nanomaterials can be used as an auxiliary means for early diagnosis of ophthalmic diseases by improving the specificity and accuracy of detection methods. Nanomaterials help clinicians and researchers delve deeper into the physiology and pathology of the eye at the nanoscale. We summarize the application of nanomaterials in the diagnosis and treatment of ophthalmic diseases in this review.

The Application of Prodrug-based Drug Delivery Strategy in Anticancer Drugs.

Cancer is the second leading cause of human death after cardiovascular disease, and the most used drugs in clinics are cytotoxic agents. However, these drugs have some inherent disadvantages, such as the risk of toxicity, low selectivity, poor solubility, and so on. To overcome these shortcomings, a variety of drug delivery strategies based on prodrugs have been developed. The application of drug delivery systems can optimize ADME properties of cytotoxic agents and improve their selectivity at the target, thereby greatly enhancing the anticancer effect in clinics. At present, it has become mainstream in drug design. This review systematically summarized the studies of prodrug- based drug delivery systems over the past five to ten years, according to four aspects, solubility, controlled release, in situ concentration, and targeting.

ZNF24 is upregulated in prostate cancer and facilitates the epithelial-to-mesenchymal transition through the regulation of Twist1.

Zinc finger protein 24 (ZNF24) has been demonstrated to regulate proliferation, differentiation and migration as well as invasion in several types of cells. However, the molecular role and clinical effects of ZNF24 in prostate cancer (PCa) remain unclear. The present study revealed that ZNF24 expression is upregulated in PCa, and associated with tumor volume, Gleason score, pathological grade and metastasis. Wound healing and Transwell invasion assays revealed that ectopic ZNF24 expression facilitated cell migration and invasion through the Twist1-induced epithelial-to-mesenchymal transition (EMT) process. In addition, colony formation and Cell Counting Kit-8 assays were used to determine the regulatory effects of ZNF24 on proliferation. The results suggested that ZNF24 also promoted cell proliferation in PCa. ZNF24 acted as an oncogene and promoted migration, invasion and EMT of PCa cells via the regulation of Twist1.