Inhalable dry powder mRNA vaccines based on extracellular vesicles

Respiratory diseases are a global burden, with millions of deaths attributed to pulmonary illnesses and dysfunctions. Therapeutics have been developed, but they present major limitations regarding pulmonary bioavailability and product stability. To circumvent such limitations, we developed room-temperature-stable inhalable lung-derived extracellular vesicles or exosomes (Lung-Exos) as mRNA and protein drug carriers. Compared with standard synthetic nanoparticle liposomes (Lipos), Lung-Exos exhibited superior distribution to the bronchioles and parenchyma and are deliverable to the lungs of rodents and nonhuman primates (NHPs) by dry powder inhalation. In a vaccine application, severe acute respiratory coronavirus 2 (SARS-CoV-2) spike (S) protein encoding mRNA-loaded Lung-Exos (S-Exos) elicited greater immunoglobulin G (IgG) and secretory IgA (SIgA) responses than its loaded liposome (S-Lipo) counterpart. Importantly, S-Exos remained functional at room-temperature storage for one month. Our results suggest that extracellular vesicles can serve as an inhaled mRNA drug-delivery system that is superior to synthetic liposomes.

Relation between Ovarian Carcinoma-Associated Antigens in Tumor Tissue and Detached Cyst Fluid Cells of Patients with Ovarian Neoplasms

Aims

The expression and potential diagnostic value of ovarian carcinoma-associated antigens were estimated in different types of epithelial ovarian neoplasms. The comparison of antigenic expression was performed on solid tumor tissues and loose cyst fluid cells in individual cases of malignant and benign ovarian neoplasms.

Methods

All studies were performed using monoclonal antibodies (mAbs) against ovarian carcinoma-associated antigens (OC125, OV-TL3, OV632, 10B, 8C) by 3-step peroxidase-antiperoxidase test.

Results

All ovarian carcinoma-associated antigens were detected in most serous and endometrioid carcinomas. In mucinous carcinomas as well as in benign ovarian neoplasms these antigens were present only in some cases. Significant inter- and intratumoral immunological heterogeneity was evident; however, the antigens detectable in tissue sections were also found in detached cyst fluid cells.

Conclusions

Our results show that mAb show OV-TL3 is the best marker for endometrioid carcinomas and confirmed that mAbs OV632, OC125 and OV-TL3 could be good complementary markers for differentiating malignant and benign lesions in the ovary. The percentage content of all ovarian carcinoma-associated antigens in solid tumors and respective cyst fluid cells was comparable.

Cytomorphologic Characterization of Cell Subsets Isolated by Density Gradient Centrifugation from Tumor Effusions of Ovarian Endometrioid Carcinoma

Aims

Cytomorphologic characterization of tumor cell subsets, according to the stage of pathologic differentiation, and comparison of cellular composition in tumor cyst and ascitic fluids were carried out on individual patients with ovarian endometrioid carcinoma.

Methods

A density gradient centrifugation technique was applied to fractionate the cells from tumor effusions.

Results

The enrichment of cell forms representing individual stages of pathologic differentiation by gradient centrifugation facilitated their cytomorphologic characterization. According to cytomorphologic features, 5 discrete cell subpopulations were identified and catalogued. The cellular composition of tumor cyst and ascitic fluids in individual patients was similar, but the number of fractions and percentage of cell subsets differed.

Conclusions

The estimation of precise cytomorphologic criteria for cell forms in tumor effusions facilitated the cytologic diagnosis of ovarian endometrioid carcinoma. The possibility to concentrate poorly differentiated, frankly malignant cell subsets in low densities could significantly improve the diagnosis of tumor effusions.

Morphologic Heterogeneity of Cell Populations Isolated by Density Gradient Centrifugation from Serous Fluids of Ovarian Tumors

The cells of tumor fluid from patients with malignant and benign serous ovarian neoplasms were fractionated using Ficoll-Uropoline density gradient centrifugation. Density distribution and morphologic characteristics of cell fractions were analyzed. It was found that serous ovarian adenocarcinomas contained three to four types of morphologically malignant cells focused in low density layers. Borderline ovarian neoplasms showed the presence of one subpopulation of cells with some features of malignancy and cells with some atypical but non-malignant features. The fluids of serous cysts contained mainly normal epithelial cells representing different stages of morphological maturity and were focused in denser layers. The results allowed us to catalogue ovarian tumor cell subpopulations present in each density fraction of individual patients and confirmed that ovarian tumors could be diagnosed by morphologic identification of cells from tumor fluids.

Comparison of cellular phenotypes in tumor cyst and ascitic fluid from ovarian serous carcinoma

Density gradient centrifugation was applied to isolate cell subsets from tumor cyst and ascitic fluid in eight patients with ovarian serous carcinoma. A comparison of cellular composition and immunologic reactivity of cells from the cysts and from ascitic fluid in each patient was performed. Some differences in density profiles were found, but in each case the consistency of morphologic cell forms in the primary tumor and ascites was documented. Immunophenotypic analyses of isolated cellular fractions using polyclonal and monoclonal antibodies against ovarian carcinoma-associated antigens showed significant immunologic intratumoral heterogeneity. However, there was a similarity of antigen expression in cells from the primary tumors and ascitic fluids. Our study indicated that morphologic and antigenic characterization of a given tumor could be determined in a single representative sample of ascitic fluid.