Cell-derived nanovesicle-mediated drug delivery to the brain: Principles and strategies for vesicle engineering.

Developing strategies toward safe and effective drug delivery into the central nervous system (CNS) with improved targeting abilities and reduced off-target effects is crucial. CNS-targeted drug carriers made of synthetic molecules raise concerns about their biodegradation, clearance, immune responses, and neurotoxicity. Cell-derived nanovesicles (CDNs) have recently been applied in CNS-targeted drug delivery, because of their intrinsic stability, biocompatibility, inherent homing capability, and the ability to penetrate through biological barriers, including the blood-brain barrier. Among these CDNs, extracellular vesicles and exosomes are the most studied because their surface can be engineered and modified to cater to brain targeting. In this review, we focus on the application of CDNs in brain-targeted drug delivery to treat neurological diseases. We cover recently developed methods of exosome derivation and engineering, including exosome-like particles, hybrid exosomes, exosome-associated adeno-associated viruses, and envelope protein nanocages. Finally, we discuss the limitations and project the future development of the CDN-based brain-targeted delivery systems, and conclude that engineered CDNs hold great potential in the treatment of neurological diseases.

Exosome for mRNA delivery: strategies and therapeutic applications.

Messenger RNA (mRNA) has emerged as a promising therapeutic molecule with numerous clinical applications in treating central nervous system disorders, tumors, COVID-19, and other diseases. mRNA therapies must be encapsulated into safe, stable, and effective delivery vehicles to preserve the cargo from degradation and prevent immunogenicity. Exosomes have gained growing attention in mRNA delivery because of their good biocompatibility, low immunogenicity, small size, unique capacity to traverse physiological barriers, and cell-specific tropism. Moreover, these exosomes can be engineered to utilize the natural carriers to target specific cells or tissues. This targeted approach will enhance the efficacy and reduce the side effects of mRNAs. However, difficulties such as a lack of consistent and reliable methods for exosome purification and the efficient encapsulation of large mRNAs into exosomes must be addressed. This article outlines current breakthroughs in cell-derived vesicle-mediated mRNA delivery and its biomedical applications.

Brain-derived extracellular vesicles: Potential diagnostic biomarkers for central nervous system diseases.

Extracellular vesicles (EVs) are membrane-enclosed nanovesicles secreted by cells into the extracellular space and contain functional biomolecules, e.g. signaling receptors, bioactive lipids, nucleic acids, and proteins, which can serve as biomarkers. Neurons and glial cells secrete EVs, contributing to various physiological and pathological aspects of brain diseases. EVs confer their role in the bidirectional crosstalk between the central nervous system (CNS) and the periphery owing to their distinctive ability to cross the unique blood-brain barrier (BBB). Thus, EVs in the blood, cerebrospinal fluid (CSF), and urine can be intriguing biomarkers, enabling the minimally invasive diagnosis of CNS diseases. Although there has been an enormous interest in evaluating EVs as promising biomarkers, the lack of ultra-sensitive approaches for isolating and detecting brain-derived EVs (BDEVs) has hindered the development of efficient biomarkers. This review presents the recent salient findings of exosomal biomarkers, focusing on brain disorders. We summarize highly sensitive sensors for EV detection and state-of-the-art methods for single EV detection. Finally, the prospect of developing advanced EV analysis approaches for the non-invasive diagnosis of brain diseases is presented.

Analysis of genetic biomarkers, polymorphisms in ADME-related genes and their impact on pharmacotherapy for prostate cancer.

Prostate cancer (PCa) is a non-cutaneous malignancy in males with wide variation in incidence rates across the globe. It is the second most reported cause of cancer death. Its etiology may have been linked to genetic polymorphisms, which are not only dominating cause of malignancy casualties but also exerts significant effects on pharmacotherapy outcomes. Although many therapeutic options are available, but suitable candidates identified by useful biomarkers can exhibit maximum therapeutic efficacy. The single-nucleotide polymorphisms (SNPs) reported in androgen receptor signaling genes influence the effectiveness of androgen receptor pathway inhibitors and androgen deprivation therapy. Furthermore, SNPs located in genes involved in transport, drug metabolism, and efflux pumps also influence the efficacy of pharmacotherapy. Hence, SNPs biomarkers provide the basis for individualized pharmacotherapy. The pharmacotherapeutic options for PCa include hormonal therapy, chemotherapy (Docetaxel, Mitoxantrone, Cabazitaxel, and Estramustine, etc.), and radiotherapy. Here, we overview the impact of SNPs reported in various genes on the pharmacotherapy for PCa and evaluate current genetic biomarkers with an emphasis on early diagnosis and individualized treatment strategy in PCa.

Biomaterial-assisted targeted and controlled delivery of CRISPR/Cas9 for precise gene editing.

RISPR-Cas9 has exhibited enormous potential in gene therapy. It can perform genome editing with single-nucleotide precision in various types of cell and tissue, providing a powerful breakthrough technology for genome editing in therapeutic development. But the limited delivery methods pose substantial challenges pertinent to safe and effective CRISPR/Cas9 delivery, thus hindering its application. These challenges should be tackled to develop next-generation genetic therapies. Biomaterial-based drug delivery systems can overcome these issues, for example using biomaterials as carriers for CRISPR/Cas9 targeted delivery, and conditional control of its function can improve precision, furnish on-demand and transient gene editing and reduce adverse consequences such as off-target events and immunogenicity, representing a promising direction for modern precision medicine. This review describes the application status and research progress of current CRISPR/Cas9 delivery approaches, including polymeric nanoparticles, liposomes, extracellular vesicles, inorganic nanoparticles and hydrogels. The unique properties of light-controlled and small-molecule drugs for spatially and temporally controlled genome editing are also illustrated. In addition, targetable delivery vehicles for the active delivery of CRISPR systems are also discussed. The perspectives to overcome the current limitations in the CRISPR/Cas9 delivery and their bench-to-bedside translation are also highlighted.

Targeting WNT signalling pathways as new therapeutic strategies for osteoarthritis.

Osteoarthritis (OA) is a highly prevalent chronic joint disease and the leading cause of disability. Currently, no drugs are available to control joint damage or ease the associated pain. The wingless-type (WNT) signalling pathway is vital in OA progression. Excessive activation of the WNT signalling pathway is pertinent to OA progression and severity. Therefore, agonists and antagonists of the WNT pathway are considered potential drug candidates for OA treatment. For example, SM04690, a novel small molecule inhibitor of WNT signalling, has demonstrated its potential in a recent phase III clinical trial as a disease-modifying osteoarthritis drug (DMOAD). Therefore, targeting the WNT signalling pathway may be a distinctive approach to developing particular agents helpful in treating OA. This review aims to update the most recent progress in OA drug development by targeting the WNT pathway. In this, we introduce WNT pathways and their crosstalk with other signalling pathways in OA development and highlight the role of the WNT signalling pathway as a key regulator in OA development. Several articles have reviewed the Wnt pathway from different aspects. This candid review provides an introduction to WNT pathways and their crosstalk with other signalling pathways in OA development, highlighting the role of the WNT signalling pathway as a key regulator in OA development with the latest research. Particularly, we emphasise the state-of-the-art in targeting the WNT pathway as a promising therapeutic approach for OA and challenges in their development and the nanocarrier-based delivery of WNT modulators for treating OA.

Chondrocyte-specific genomic editing enabled by hybrid exosomes for osteoarthritis treatment.

Rationale: A cell-specific delivery vehicle is required to achieve gene editing of the disease-associated cells, so the hereditable genome editing reactions are confined within these cells without affecting healthy cells. A hybrid exosome-based nano-sized delivery vehicle derived by fusion of engineered exosomes and liposomes will be able to encapsulate and deliver CRISPR/Cas9 plasmids selectively to chondrocytes embedded in articular cartilage and attenuate the condition of cartilage damage. Methods: Chondrocyte-targeting exosomes (CAP-Exo) were constructed by genetically fusing a chondrocyte affinity peptide (CAP) at the N-terminus of the exosomal surface protein Lamp2b. Membrane fusion of the CAP-Exo with liposomes formed hybrid CAP-exosomes (hybrid CAP-Exo) which were used to encapsulate CRISPR/Cas9 plasmids. By intra-articular (IA) administration, hybrid CAP-Exo/Cas9 sgMMP-13 entered the chondrocytes of rats with cartilage damages that mimicked the condition of osteoarthritis. Results: The hybrid CAP-Exo entered the deep region of the cartilage matrix in arthritic rats on IA administration, delivered the plasmid Cas9 sgMMP-13 to chondrocytes, knocked down the matrix metalloproteinase 13 (MMP-13), efficiently ablated the expression of MMP-13 in chondrocytes, and attenuated the hydrolytic degradation of the extracellular matrix proteins in the cartilage. Conclusion: Chondrocyte-specific knockdown of MMP-13 mitigates or prevents cartilage degradation in arthritic rats, showing that hybrid CAP-Exo/Cas9 sgMMP-13 may alleviate osteoarthritis.

Cell-derived extracellular vesicles for CRISPR/Cas9 delivery: engineering strategies for cargo packaging and loading.

Genome editing technology has emerged as a potential therapeutic tool for treating incurable diseases. In particular, the discovery of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas systems and the design of single-guide RNAs (sgRNAs) have revolutionized genome editing applications. Unfortunately, compared with the rapid development of gene-editing tools, the progress in the development of delivery technologies is lagging behind and thus limiting the clinical application of genome editing. To overcome these limitations, researchers have investigated various delivery systems, including viral and non-viral vectors for delivering CRISPR/Cas and sgRNA complexes. As natural endogenous nanocarriers, extracellular vesicles (EVs) present advantages of biocompatibility, low immunogenicity, stability, and high permeability, making them one of the most promising drug delivery vehicles. This review provides an overview of the fundamental mechanisms of EVs from the aspects of biogenesis, trafficking, cargo delivery, and function as nanotherapeutic agents. We also summarize the latest trends in EV-based CRISPR/Cas delivery systems and discuss the prospects for future development. In particular, we put our emphasis on the state-of-the-art engineering strategies to realize efficient cargo packaging and loading. Altogether, EVs hold promise in bridging genome editing in the laboratory and clinical applications of gene therapies by providing a safe, effective, and targeted delivery vehicle.

Size-transformable nanohybrids with pH/redox/enzymatic sensitivity for anticancer therapy.

A lack of sufficient tumor penetration and low delivery efficiency are the main reasons for the limited clinical applications of nanocarriers in cancer treatment. Tumor microenvironment responsive drug delivery systems have been attracting great interest in cancer therapy as the desired drug release can be achieved in the disease sites for optimal treatment efficiency. In this work, we developed a biodegradable nanohybrid drug delivery system with pH/redox/enzymatic sensitivity by the simple assembly of bovine serum albumin nano-units (about 5 nm) onto graphene oxide nanosheets in the presence of a naturally originating protein (gelatin). The nanoparticles can maintain a constant size under physiological conditions, while releasing 5 nm nano-units containing the drug upon triggering by the environment-mimicking protease highly expressed in the tumor microenvironment. Furthermore, after reaching the tumor tissue, the acidic, reductive, and enzymatic microenvironments turned on the switch for DOX release, and the combination of chemotherapy and photothermal therapy was achieved under the trigger of near-infrared light. The nanosystems have the potential to improve the penetration ability through the depth of the tumor tissue to enhance drug intracellular delivery and antitumor bioactivity.

Causes of Acute Peritonitis and Its Complication.

Introduction Peritonitis is a significant cause of morbidity and mortality in surgical settings. Coexisting premorbid illness and postoperative complications were found to be associated with death. This study aimed to analyze various etiologies that cause peritonitis and shed light on the factors responsible for unsatisfactory results. Method This longitudinal study included 309 patients above 12 years of age, of either gender, with confirmed diagnosis of peritonitis. Exploratory laparotomy was done to identify the cause of peritonitis. Patients were monitored postoperatively till their discharge or death for the development of complications. Results Our results showed that the most common cause of acute peritonitis was duodenal perforation (26.2%), followed by typhoid ileal perforation (24.2%) and ruptured appendix (16.8%). At least one complication was observed in 31% of the participants. The most common complication was dehydration (18.8%), followed by septicemia (11.3%) and paralytic ileus (6.4%). Ten (3.2%) patients died in the hospital. Conclusions Acute peritonitis is a serious surgical emergency caused by a number of diseases. Early surgical treatment along with antibiotics, followed by aggressive resuscitation can yield improved outcomes in patients with peritonitis.

The thermal/pH-sensitive drug delivery system encapsulated by PAA based on hollow hybrid nanospheres with two silicon source.

The synthesis of drug delivery systems based on hollow mesoporous silica nanoparticles (MSNs) is still a major challenge. In this work, the hollow hybrid MSNs were successfully prepared by cetyltrimethylammonium bromide-directed sol-gel process and one-step hydrothermal treatment process. The hollow hybrid MSNs had hybrid ethane-bridged frameworks with the uniform particle size (250 nm) and mesoporous pore diameter (3.7 nm). The polyacrylic acid (PAA) encapsulated drug delivery system based on hollow hybrid MSNs was prepared by using silanization, surface modification, doxorubicin hydrochloride (DOX) loading, and PAA coating. Drug encapsulation and release behavior at different temperatures and pH were studied by using DOX as a model guest molecule. The results displayed that the modified hollow ethane-bridged MSNs possessed good biocompatibility and excellent thermal/pH-dual-sensitive drug release property. This novel thermal/pH-sensitive drug delivery system based on hollow ethane-bridged MSNs has the advantages of feasible synthesis, no cytotoxicity, and good drug loading capacity, which may have potential applications in the anticancer therapy.

Long-Term X-ray Findings in Patients With Coronavirus Disease-2019.

INTRODUCTION: Reverse transcription-polymerase chain reaction (RT-PCR) and chest X-ray (CXR) are commonly used techniques for diagnosing and assessing prognosis in patients with coronavirus disease-2019 (COVID-19). This study aims to highlight the long-term radiological findings observed on CXR after recovery, in patients with COVID-19. This will help identify patients suffering from long-term consequences of COVID-19 and help them provide adequate care. METHODS: This study was conducted in the COVID-19 unit of a tertiary care hospital, Pakistan from August 2020 to February 2021. CXR of patients who were being discharged after negative PCR was done. Participants with positive X-ray findings, which included consolidation, reticular thickening, ground-glass opacities (GGO), pulmonary nodules, and pleural effusions, were enrolled in the study after getting informed consent. All findings were recorded in a self-structured questionnaire. Participants were scheduled to come for follow-up on day 30 after their initial CXR, where their CXR was repeated. RESULT: Our results showed that n=429 (60.2%) participants had positive CXR at the time of discharge. After 30 days, n=371 participants returned for a follow-up X-ray. Out of the 371 participants, after 30 days, 123 participants still had positive CXR. Fatigue (41.4%) was the common symptom after 30 days. The most common finding was consolidation (82.1%), followed by reticular thickening (23.5%) on day 30. CONCLUSION: In this study, although most of the patients completely recovered serologically from COVID-19, they still had radiological findings in their chest X-rays. Radiological findings are especially important in predicting the clinical course of the disease and may be used to monitor long-term complications.