Plasmodium falciparum sexual parasites develop in human erythroblasts and affect erythropoiesis.

Plasmodium falciparum gametocytes, the sexual stage responsible for malaria parasite transmission from humans to mosquitoes, are key targets for malaria elimination. Immature gametocytes develop in the human bone marrow parenchyma, where they accumulate around erythroblastic islands. Notably though, the interactions between gametocytes and this hematopoietic niche have not been investigated. Here, we identify late erythroblasts as a new host cell for P falciparum sexual stages and show that gametocytes can fully develop inside these nucleated cells in vitro and in vivo, leading to infectious mature gametocytes within reticulocytes. Strikingly, we found that infection of erythroblasts by gametocytes and parasite-derived extracellular vesicles delay erythroid differentiation, thereby allowing gametocyte maturation to coincide with the release of their host cell from the bone marrow. Taken together, our findings highlight new mechanisms that are pivotal for the maintenance of immature gametocytes in the bone marrow and provide further insights on how Plasmodium parasites interfere with erythropoiesis and contribute to anemia in malaria patients.

Plastic Surgery Away Rotations During the Coronavirus Disease Pandemic: A Virtual Experience.

BACKGROUND: Plastic surgery has traditionally been a specialty that places a strong emphasis on away rotations during the final year of medical school. These rotations allow the program and residency candidates to become better acquainted and are often crucial, as a large portion of applicants match at programs where they rotated. The coronavirus disease 2019 (COVID-19) pandemic forced many institutions to modify their educational curriculums when away rotations were canceled. We present our experience creating and implementing a virtual plastic surgery rotation. METHODS: Our virtual program was designed to mirror the in-person away rotations as much as possible. Prerotation and postrotation surveys from the students as well as feedback interviews with the students, residents, and faculty were used to gather information on the experience. RESULTS: We created a 2-week curriculum including approximately 20 hours of lecture time, 28 hours of operating room time, 2.5 hours of one-on-one mentorship, and 3 hours of social opportunities. Students reported that they learned more about plastic surgery and the residency program, but in contrast to this, some found it difficult to make an impression. CONCLUSIONS: We developed a novel 2-week virtual curriculum that provided visiting medical students from across the country an opportunity to learn more about plastic surgery and our residency program. Virtual learning is becoming a vital part of education, and our study provides pearls and pitfalls when structuring these experiences.

Effect of stroma on the behavior of temoporfin-loaded lipid nanovesicles inside the stroma-rich head and neck carcinoma spheroids.

BACKGROUND: Despite the highly expected clinical application of nanoparticles (NPs), the translation of NPs from lab to the clinic has been relatively slow. Co-culture 3D spheroids account for the 3D arrangement of tumor cells and stromal components, e.g., cancer-associated fibroblasts (CAFs) and extracellular matrix, recapitulating microenvironment of head and neck squamous cell carcinoma (HNSCC). In the present study, we investigated how the stroma-rich tumor microenvironment affects the uptake, penetration, and photodynamic efficiency of three lipid-based nanoformulations of approved in EU photosensitizer temoporfin (mTHPC): Foslip® (mTHPC in conventional liposomes), drug-in-cyclodextrin-in-liposomes (mTHPC-DCL) and extracellular vesicles (mTHPC-EVs). RESULTS: Collagen expression in co-culture stroma-rich 3D HNSCC spheroids correlates with the amount of CAFs (MeWo cells) in individual spheroid. The assessment of mTHPC loading demonstrated that Foslip®, mTHPC-DCL and mTHPC-EVs encapsulated 0.05 × 10- 15 g, 0.07 × 10- 15 g, and 1.3 × 10- 15 g of mTHPC per nanovesicle, respectively. The mid-penetration depth of mTHPC NPs in spheroids was 47.8 µm (Foslip®), 87.8 µm (mTHPC-DCL), and 49.7 µm (mTHPC-EVs), irrespective of the percentage of stromal components. The cellular uptake of Foslip® and mTHPC-DCL was significantly higher in stroma-rich co-culture spheroids and was increasing upon the addition of serum in the culture medium. Importantly, we observed no significant difference between PDT effect in monoculture and co-culture spheroids treated with lipid-based NPs. Overall, in all types of spheroids mTHPC-EVs demonstrated outstanding total cellular uptake and PDT efficiency comparable to other NPs. CONCLUSIONS: The stromal microenvironment strongly affects the uptake of NPs, while the penetration and PDT efficacy are less sensitive to the presence of stromal components. mTHPC-EVs outperform other lipid nanovesicles due to the extremely high loading capacity. The results of the present study enlarge our understanding of how stroma components affect the delivery of NPs into the tumors.

Breaking Down Silos: Collaboration in Head and Neck Reconstruction Research.

BACKGROUND: Collaboration has been shown to be beneficial when we have complex problems and highly specialized groups, such as in head and neck reconstruction. Otolaryngology, plastic surgery, and oral maxillofacial surgeons perform head and neck reconstruction research. While the specialties represent unique backgrounds, the degree of interdisciplinary collaboration and subtopic focus is unknown. We sought to describe the frequency of interinstitutional interdisciplinary collaboration and examine the association of specialty with research subtopics. METHODS: Oral presentations from 2014 to 2018 focused on head and neck reconstruction or associated principles at the main reconstructive academic meetings in otolaryngology (American Head and Neck Society), plastic surgery (American Society for Reconstructive Microsurgery), and oral maxillofacial surgery (American Association of Oral and Maxillofacial Surgeons) were reviewed. Author specialty and institution data were recorded. All abstracts were assigned a research subtopic, chosen based on identified themes. Subtopic frequencies among the specialties were compared. RESULTS: Thirteen of 88 (15%) US institutions participate in interdisciplinary collaboration in head and neck reconstruction research. Of the remaining institutions, 23 (31%) have researchers performing parallel work and not collaborating. Certain research subtopics were more often presented by each specialty, representing differing interests. CONCLUSION: Collaboration among head and neck reconstruction research at the US institutions is low compared with the potential. Specialties focus on different research subtopics, and therefore can benefit from working together.

Nanoparticle-based hyperthermia, a local treatment modulating the tumor extracellular matrix.

The structural complexity and physical properties of the tumor microenvironment negatively affect the penetration and efficiency of conventional anticancer drugs. While previously underestimated, the tumor microenvironment now becomes a potential target for cancer treatment. This microenvironment can be modulated either systemically by pharmacological means, or locally, through physical effects mediated by certain nanoparticles. Some of them, such as magnetic, plasmonic or carbon-based nanoparticles, can generate heat on demand in a spatially and temporally controlled manner. In addition, the nanoparticles can be either activated by light or magnetic stimuli. The impact of the resulting local heating can be observed on the ultrastructural level, as it strongly affects the organization of collagen fibers, and on the macroscopic level, since the thermal damages alter the mechanical properties of the tumor. Nanoparticle-based hyperthermia thus improves the effect of conventional anticancer drugs, as it allows their better penetration through the altered extracellular matrix. Here we suggest the use of nanoparticle-generated hyperthermia, obtained after magnetic or light activation, as an adjuvant treatment to prime the tumor microenvironment and improve the efficacy of chemotherapy.

Complex Orofacial Reconstruction with the Intrinsic Chimeric Flap.

Background Ablation of locally advanced or recurrent head and neck cancer often results in large composite orofacial defects with limited recipient vessels. These complex defects lend well to intrinsic chimeric flap reconstruction, which allows greater ability to inset various flap component tissue types than composite flaps and requires only one set of microvascular anastomoses. Methods A retrospective chart review was performed on all patients who underwent orofacial reconstruction with an intrinsic chimeric free flap from 2002 to 2015. Flaps with only one tissue type, such as two separate skin paddles with no additional component, were not considered chimeric flaps and therefore not included in this report. Patient demographic data, defect, and flap characteristics, as well as complications and outcomes were analyzed to create a guide for flap selection. Univariate and multivariate analysis was performed to determine risk factors for flap take-back and failure. Results Seventy-five patients underwent orofacial intrinsic chimeric free flap reconstruction. Results were organized based on defect characteristics to create a guide for flap selection. The number of chimeric flap components and operation duration were independently statistically associated with flap take-backs (p < 0.05). There were two (3%) total and five (7%) partial flap losses. Average follow-up time was 32.7 months. Conclusions Intrinsic chimeric flaps provide a versatile and elegant reconstructive option for a variety of complex orofacial defects. We provide a guide to facilitate decision making in flap selection for these challenging reconstructions and report factors associated with flap take-backs and losses.

Design of Magnetic Polymeric Particles as a Stimulus-Responsive System for Gastric Antimicrobial Therapy.

The treatment of peptic ulcers induced by H. pylori remains challenging due to the deep mucous layer location of bacteria preventing antimicrobial drug access. The present work aimed to design and evaluate in vitro dual responsive (both pH and magnetic field-sensitive) polymeric magnetic particles loaded with amoxicillin as a smart drug carrier for deep mucous layer penetration and in situ drug release. Magnetite particles were produced by the co-precipitation method and subsequently coated with the Eudragit®S100 and amoxicillin by using the spray-drying technique. The physicochemical characterization of the obtained particles was carried out by optical and scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption isotherms, and vibrating sample magnetometry. Additionally, drug release tests and antibacterial activity tests were evaluated in vitro. Microparticles presented 17.2 ± 0.4 µm in size and their final composition was 4.3 ± 1.5% of amoxicillin, 87.0 ± 2.3% of Eudragit, and 9.0 ± 0.3% of magnetite. They were both pH and magnetic field responsive while presenting antimicrobial activity. On one side, magnetic field responsiveness of particles is expected to prompt them to reach bacterium niche in deep mucous layer by means of magnetic forces. On the other side, pH responsiveness is expected to enable drug release in the neutral pH of the deep mucous layer, preventing undesired delivery in the acidic gastric lumen. Smart microparticles were designed presenting both pH and magnetic field responsiveness as well as antimicrobial activity. These may be promising assets for peptic ulcer treatment.

Vascularized lymph node transfer and lymphovenous bypass: Novel treatment strategies for symptomatic lymphedema.

Lymphedema is a debilitating disease that is commonly caused by cancer and it is treatments in the developed world. Surgery is an option for refractory disease. Lymphovenous bypass and vascularized lymph node transfer are newer modalities that show great promise. Further work is necessary to determine proper patient selection and ensure minimum donor site morbidity. Liposuction and direct excision still have a role, especially in advanced cases. Further investigations into prevention of iatrogenic lymphedema are underway. J. Surg. Oncol. 2016;113:932-939. © 2016 Wiley Periodicals, Inc.

The Effect of Contralateral Prophylactic Mastectomy on Perioperative Complications in Women Undergoing Immediate Breast Reconstruction: A NSQIP Analysis.

BACKGROUND: Women with breast cancer are increasingly choosing to undergo contralateral prophylactic mastectomy (CPM) despite questionable survival benefit and limited data on added risks. Little is known about differences in perioperative complications between women who undergo bilateral mastectomy (BM) versus unilateral mastectomy (UM) with reconstruction. METHODS: The American College of Surgeons National Surgery Quality Improvement Program Participant Use Files (2005-2013) were used to identify women with unilateral breast cancer who underwent UM or BM with reconstruction. Adjusted 30-day complications were compared between UM and BM groups using logistic regression models. RESULTS: A total of 20,501 patients were identified, of whom 35.3 % underwent BM. Of these, 84.3 % had implant reconstruction and 15.7 % had autologous reconstruction. For all women, BM was associated with longer hospital stays (adjusted odds ratio [aOR] 1.98-2.09, p < 0.001) and a higher transfusion rate than UM (aOR 2.52-3.06, p < 0.001). BM with implant reconstruction was associated with a modestly increased reoperation rate (aOR 1.15, p = 0.029). BM with autologous reconstruction was associated with a higher wound disruption rate (aOR 2.51, p = 0.015). Surgical site infections, prosthesis failure, and medical complications occurred at similar rates in UM and BM groups. CONCLUSIONS: CPM is associated with significant increases in some, but not all, surgical site complications. CPM does not increase the likelihood of medical complications, which are generally infrequent.

Combining magnetic nanoparticles with cell derived microvesicles for drug loading and targeting.

Inspired by microvesicle-mediated intercellular communication, we propose a hybrid vector for magnetic drug delivery. It consists of macrophage-derived microvesicles engineered to enclose different therapeutic agents together with iron oxide nanoparticles. Here, we investigated in vitro how magnetic nanoparticles may influence the vector effectiveness in terms of drug uptake and targeting. Human macrophages were loaded with iron oxide nanoparticles and different therapeutic agents: a chemotherapeutic agent (doxorubicin), tissue-plasminogen activator (t-PA) and two photosensitizers (disulfonated tetraphenyl chlorin-TPCS2a and 5,10,15,20-tetra(m-hydroxyphenyl)chlorin-mTHPC). The hybrid cell microvesicles were magnetically responsive, readily manipulated by magnetic forces and MRI-detectable. Using photosensitizer-loaded vesicles, we showed that the uptake of microvesicles by cancer cells could be kinetically modulated and spatially controlled under magnetic field and that cancer cell death was enhanced by the magnetic targeting. From the clinical editor: In this article, the authors devised a biogenic method using macrophages to produce microvesicles containing both iron oxide and chemotherapeutic agents. They showed that the microvesicles could be manipulated by magnetic force for targeting and subsequent delivery of the drug payload against cancer cells. This smart method could provide a novel way for future fight against cancer.

Transcriptome Profiling of Wild Arachis from Water-Limited Environments Uncovers Drought Tolerance Candidate Genes.

Peanut (Arachis hypogaea L.) is an important legume cultivated mostly in drought-prone areas where its productivity can be limited by water scarcity. The development of more drought-tolerant varieties is, therefore, a priority for peanut breeding programs worldwide. In contrast to cultivated peanut, wild relatives have a broader genetic diversity and constitute a rich source of resistance/tolerance alleles to biotic and abiotic stresses. The present study takes advantage of this diversity to identify drought-responsive genes by analyzing the expression profile of two wild species, Arachis duranensis and Arachis magna (AA and BB genomes, respectively), in response to progressive water deficit in soil. Data analysis from leaves and roots of A. duranensis (454 sequencing) and A. magna (suppression subtractive hybridization (SSH)) stressed and control complementary DNA (cDNA) libraries revealed several differentially expressed genes in silico, and 44 of them were selected for further validation by quantitative RT-PCR (qRT-PCR). This allowed the identification of drought-responsive candidate genes, such as Expansin, Nitrilase, NAC, and bZIP transcription factors, displaying significant levels of differential expression during stress imposition in both species. This is the first report on identification of differentially expressed genes under drought stress and recovery in wild Arachis species. The generated transcriptome data, besides being a valuable resource for gene discovery, will allow the characterization of new alleles and development of molecular markers associated with drought responses in peanut. These together constitute important tools for the peanut breeding program and also contribute to a better comprehension of gene modulation in response to water deficit and rehydration.

Xyloglucan-derivatized films for the culture of adherent cells and their thermocontrolled detachment: a promising alternative to cells sensitive to protease treatment.

By taking advantage of a natural and abundant polymer as well as a straightforward film formation technique, this paper focuses on the conception and use of a new alternative tool for thermo-controlled cell detachment. Thermoresponsive xyloglucan was produced after partial galactose removal by a 24 h reaction with ß-galactosidase. The obtained polymer (T24) was then activated by reaction with 4-nitrophenyl chloroformate (NPC) in order to graft a cyclic peptide presenting an arginine-glycine-aspartic acid (RGD) motif. The effect of RGD grafting on the sol-gel transition temperature of T24 is evaluated by rheological measurements. Solvent-casted films of T24-RGD successfully promoted cell adhesion, proliferation, and thermo-controlled detachment. The presented approach is a new alternative for cells sensitive to the proteolytic treatment routinely used for cell detachment. Because the RGD sequence used herein is widely recognized by different cell types, this protocol may be extended to other cells. Besides, the presented chemical route can be applied to different peptide sequences.

The antihyperglycemic and hypolipidemic activities of a sulfur-oxidovanadium(IV) complex.

This study describes the synthesis, characterization, and biological activity of a new class of antidiabetic oxidovanadium(IV)-complexes with S2O2 coordination mode. The target complex 3,6-dithio-1,8-octanediolatooxidovanadium(IV), abbreviated as ([VIVO(octd)]), where octd = 3,6-dithio-1,8-octanediol, is formed from the reaction between the 3,6-dithio-1,8-octanediol and vanadyl sulfate (VIVOSO4). The effects of treatment with ([VIVO(octd)] on blood glucose, lipidic profile, body weight, food intake, water intake, urinary volume, glycogen levels, and biomarkers for liver toxicity were investigated using a streptozotocin (STZ)-induced diabetic Wistar rats model. The results have shown that the [VIVO(octd)] complex caused a significant decrease in blood glucose (247.6 ± 19.3 mg/dL vs 430.1 ± 37.6 mg/dL diabetic group, p < 0.05), triglycerides (TG, 50%) and very low-density cholesterol (VLDL-C, 50%) levels in STZ-diabetic rats after 3 weeks of treatment. The [VIVO(octd)] has shown antihyperglycemic activity in diabetic rats as well as a reduction in elevated lipid levels. Time-dependent studies using EPR and 51V NMR spectroscopy of [VIVO(octd)] were done in aqueous solutions to determine the complex stability and species present in the oral gavage solution used for complex administration. The spectroscopic studies have shown that the antidiabetic/hypolipidemic activity could be attributed to [VIVO(octd)], vanadium species resulting from redox processes, the hydrolysis of [VIVO(octd)] and its decomposition products, or some combination of these factors. In summary, the oxidovanadium(IV) complex containing the S2O2 donor ligand has desirable antidiabetic properties eliminating the symptoms of Diabetes mellitus and its comorbidities.

Resolution of MoS2 Nanosheets-Induced Pulmonary Inflammation Driven by Nanoscale Intracellular Transformation and Extracellular-Vesicle Shuttles.

Pulmonary exposure to some engineered nanomaterials can cause chronic lesions as a result of unresolved inflammation. Among 2D nanomaterials and graphene, MoS2 has received tremendous attention in optoelectronics and nanomedicine. Here an integrated approach is proposed to follow up the transformation of MoS2 nanosheets at the nanoscale and assesss their impact on lung inflammation status over 1 month after a single inhalation in mice. Analysis of immune cells, alveolar macrophages, extracellular vesicles, and cytokine profiling in bronchoalveolar lavage fluid (BALF) shows that MoS2 nanosheets induced initiation of lung inflammation. However, the inflammation is rapidly resolved despite the persistence of various biotransformed molybdenum-based nanostructures in the alveolar macrophages and the extracellular vesicles for up to 1 month. Using in situ liquid phase transmission electron microscopy experiments, the dynamics of MoS2 nanosheets transformation triggered by reactive oxygen species could be evidenced. Three main transformation mechanisms are observed directly at the nanoscale level: 1) scrolling of the dispersed sheets leading to the formation of nanoscrolls and folded patches, 2) etching releasing soluble MoO4 - , and 3) oxidation generating oxidized sheet fragments. Extracellular vesicles released in BALF are also identified as a potential shuttle of MoS2 nanostructures and their degradation products and more importantly as mediators of inflammation resolution.

Hispanic ethnicity and fatal fall risk: do age, gender, and community modify the relationship?

BACKGROUND: Hispanic ethnicity is associated with a reduced risk of fatal falls in the elderly despite lower socioeconomic standing. The factors responsible for this "Hispanic paradox" are unknown. We hypothesized that age and gender would modify this relationship and that the association would be accentuated in a community with prominent Hispanic culture. MATERIALS AND METHODS: The number of fatal falls in a 3-year period in the United States (US) and in Miami-Dade County, Florida (MDC) were obtained through the CDC's WISQARS database and the Florida Office of Vital Statistics. US Census Bureau data were used to define the total at-risk populations by age group and gender. Age group- and gender-specific ratios of the risk of fatal fall in Hispanic to white non-Hispanic individuals were calculated. RESULTS: In the US and MDC, Hispanic ethnicity was associated with a reduced risk of fatal fall across all age and gender subgroups. In the US, the risk reduction associated with Hispanic ethnicity grew from 11% and 23% in 65- to 74-year-old men and women, respectively, to 43% for both men and women over 84-years-old. This relationship was stronger in MDC than nationally in five of the six age and gender subgroups examined. CONCLUSIONS: Older individuals, women, and residents of communities with prominent Hispanic culture have the greatest reduction in fatal fall risk associated with Hispanic ethnicity.

Cellular transfer of magnetic nanoparticles via cell microvesicles: impact on cell tracking by magnetic resonance imaging.

PURPOSE: Cell labeling with magnetic nanoparticles can be used to monitor the fate of transplanted cells in vivo by magnetic resonance imaging. However, nanoparticles initially internalized in administered cells might end up in other cells of the host organism. We investigated a mechanism of intercellular cross-transfer of magnetic nanoparticles to different types of recipient cells via cell microvesicles released under cellular stress. METHODS: Three cell types (mesenchymal stem cells, endothelial cells and macrophages) were labeled with 8-nm iron oxide nanoparticles. Then cells underwent starvation stress, during which they produced microvesicles that were subsequently transferred to unlabeled recipient cells. RESULTS: The analysis of the magnetophoretic mobility of donor cells indicated that magnetic load was partially lost under cell stress. Microvesicles shed by stressed cells participated in the release of magnetic label. Moreover, such microvesicles were uptaken by naïve cells, resulting in cellular redistribution of nanoparticles. Iron load of recipient cells allowed their detection by MRI. CONCLUSIONS: Cell microvesicles released under stress may be disseminated throughout the organism, where they can be uptaken by host cells. The transferred cargo may be sufficient to allow MRI detection of these secondarily labeled cells, leading to misinterpretations of the effectiveness of transplanted cells.

Extracellular Vesicles in Transplantation.

Extracellular vesicles (EVs) have been extensively studied in the last two decades. It is now well documented that they can actively participate in the activation or regulation of immune system functions through different mechanisms, the most studied of which include protein-protein interactions and miRNA transfers. The functional diversity of EV-secreting cells makes EVs potential targets for immunotherapies through immune cell-derived EV functions. They are also a potential source of biomarkers of graft rejection through donor cells or graft environment-derived EV content modification. This review focuses on preclinical studies that describe the role of EVs from different cell types in immune suppression and graft tolerance and on the search for biomarkers of rejection.

Hispanic ethnicity and unintentional injury mortality in the elderly.

BACKGROUND: Unintentional injury is a leading cause of preventable mortality in elderly populations and is most often related to accidental falls and motor vehicle accidents. Hispanic ethnicity has been previously associated with decreased risk of accidental fall death as well as improved outcomes in other health states, the "Hispanic paradox." A timely analysis of national data with consideration for multiple injury types and age could provide insight into this epidemiologic phenomenon and help guide the use of prevention efforts. MATERIALS AND METHODS: Search of the Center for Disease Control's WISQARS database was performed to identify the number of fatalities in the U.S. between 2003 and 2006 by age group, gender, Hispanic ethnicity, and injury type. Total U.S. population and group populations for the years examined were obtained from the U.S. Census Bureau's American Community Survey for each year. Mortality was calculated as fatalities over the total group population for the years examined. RESULTS: Independent of gender and age group, elderly Hispanics were at decreased risk of death from accidental fall or as an occupant in a motor vehicle accident, but increased risk of pedestrian fatality compared with white-NH. CONCLUSIONS: The reduced fall and occupant mortality seen in elderly Hispanic populations may come at the cost of increased pedestrian-related mortality. This is consistent with and likely reflects differences in culture, socioeconomic status, and geographic distribution for the U.S. Hispanic population. Effective targeting of injury prevention programs, especially community based, should consider the role of Hispanic ethnicity and its impact on lifestyle.

Thinking Quantitatively of RNA-Based Information Transfer via Extracellular Vesicles: Lessons to Learn for the Design of RNA-Loaded EVs.

Extracellular vesicles (EVs) are 50-1000 nm vesicles secreted by virtually any cell type in the body. They are expected to transfer information from one cell or tissue to another in a short- or long-distance way. RNA-based transfer of information via EVs at long distances is an interesting well-worn hypothesis which is ~15 years old. We review from a quantitative point of view the different facets of this hypothesis, ranging from natural RNA loading in EVs, EV pharmacokinetic modeling, EV targeting, endosomal escape and RNA delivery efficiency. Despite the unique intracellular delivery properties endowed by EVs, we show that the transfer of RNA naturally present in EVs might be limited in a physiological context and discuss the lessons we can learn from this example to design efficient RNA-loaded engineered EVs for biotherapies. We also discuss other potential EV mediated information transfer mechanisms, among which are ligand-receptor mechanisms.

[Therapeutic applications of extracellular vesicles]. / Applications thérapeutiques des vésicules extracellulaires.

Extracellular vesicles, secreted spontaneously or in response to stress by all cell types, are proposed as alternative biotherapies to cellular therapies and to synthetic nanomedicines. Their logistical advantages (storage, stability, availability, tolerance), their ability to cross biological barriers, to deliver their contents (proteins, lipids and nucleic acids) in order to modify their target cells, as well as their immunomodulatory and regenerative activities, are of growing interest for a very wide spectrum of diseases. Here we review the challenges to bring these biotherapies to the clinic and discuss some promising applications in cancer and regenerative medicine.

TITLE: Applications thérapeutiques des vésicules extracellulaires. ABSTRACT: Les vésicules extracellulaires, sécrétées spontanément ou en réponse à un stress par tous les types cellulaires, sont proposés comme des biothérapies alternatives aux thérapies cellulaires et aux nanomédicaments synthétiques. Leurs atouts logistiques (stockage, stabilité, disponibilité, tolérance), leur capacité à franchir les barrières biologiques, à délivrer leurs contenus (protéines, lipides et acides nucléiques) pour modifier leurs cellules cibles, ainsi que leurs activités immunomodulatrice et régénérative, suscitent un intérêt grandissant pour un très large spectre de maladies. Cette synthèse présente les défis qui restent à relever pour appliquer ces biothérapies en clinique. Quelques applications prometteuses dans les domaines du cancer et de la médecine régénérative seront proposées.