Nanoparticle-functionalized dressings for the treatment of third-degree skin burns - histopathological and immunohistochemical study.

Skin burns are one of the most common injuries associated with increased morbidity and mortality, especially in the children and the elderlies. Severe burns, especially, result in a systemic immune and inflammatory response, which may reflect in multiple organ insufficiency, and a fast and effective local restorative process is essential for functionality recovering, as well as for interrupting the generalized systemic response. We have aimed here to assess the effect of different wound dressings in what it regards the morphology and clinical restoration after a skin burn. On a rat animal model, we have evaluated the macroscopic and histopathological features of controlled third degree skin burns in control animals versus treatments with local dressings of silver sulfadiazine (SDA) cream, simple gel (G), gel + silver nanoparticles (AgNPs) (G+NPS), gel + exosomes (G+EXO) and gel + AgNPs + exosomes (Gel+NPS+EXO), at 14 days and, respectively, 21 days after the lesion. Tissue fragments were harvested and processed for histopathology and immunohistochemistry. Immunofluorescence was utilized to evaluate the maturity of underlaying granulation tissue based on double stainings for smooth muscle actin (SMA) and cluster of differentiation 31 (CD31). Our study showed variability in what it regards the vessel density and immunoexpression of SMA between the treatments, and image analysis revealed that most SMA reduction and blood vessel density reduction in the maturing granulation tissue occurred for the G+NPS and G+NPS+EXO treatments. A complete re-epithelization was also observed for the G+NPS+EXO treatment. Overall, our results show that improved topic treatments promote faster re-epithelization and reparation of the dermis after skin burn lesions, providing thus an avenue for new treatments that aim both local recuperation and systemic infection prevention.

The Effect of Silver Nanoparticles on Antioxidant/Pro-Oxidant Balance in a Murine Model.

This study aimed to evaluate the subacute effect of two types of Ag-NPs(EG-AgNPs and PVP-EG-AgNPs) on antioxidant/pro-oxidant balance in rats. Seventy Wistar rats (35 males and 35 females) were divided in 7 groups and intraperitoneally exposed for 28 days to 0, 1, 2 and 4 mg/kg bw/day EG-Ag-NPs and 1, 2 and 4 mg/kg bw/day PVP- EG-Ag-NPs. After 28 days, the blood was collected, and the total antioxidant capacity (TAC), thiobarbituric reactive species (TBARS),protein carbonyl (PROTC) levels, reduced glutathione (GSH) levels and catalase (CAT) activity were determined. EG-Ag-NPs determined protective antioxidant effects in a dose-dependent manner. The exposure to the 4 mg/kg bw/day EG-Ag-NPs determines both in males and females a significant increase in TAC and CAT and a significant decrease in TBARS and PROTC only in females. The PVP-EG-AgNPs showed a different trend compared to EG-AgNPs. At 4 mg/kg bw/day the PVP-EG-AgNPs induce increased PROTC levels and decreased GSH (males and females) and TAC levels (males). The different mechanisms of EG-AgNPs and PVP-EG-AgNPs on antioxidant-/pro-oxidant balance can be explained by the influence of coating agent used for the preparation of the nanoparticles in the formation and composition of protein corona that influence their pathophysiology in the organism.

The clinical-morphological profile of tuberculous pleurisies - our experience in relation to literature data.

AIM: The authors made a morphological evaluation of pleural tissue fragments from patients hospitalized in Thoracic Surgery Department of the Emergency County Hospital of Craiova, Romania, over a period of 26 years, diagnosed with tuberculous lesions in the Pathology Department of the same Hospital. PATIENTS, MATERIALS AND METHODS: The studied material consisted of pleural tissue samples taken by biopsy or surgical excision from 39 cases coming out of 841 patients investigated in the above-mentioned period of time and diagnosed from histological point of view with tuberculosis (TB). Granuloma cell population was assessed using immunohistochemical method. For diagnostic confirmation, Ziehl-Neelsen staining has been used as a rule but, in some cases, immunohistochemistry was also used. RESULTS: TB lesions predominated in men usually around or over 50 years old. The diagnostic was suspected in almost half of the cases. Right cavity was more affected and the extended fibrosis was present in a significant number of cases. The inflammatory conflict was of reactive type, with giant Langhans cells granulomas and acidophilic necrosis but sometimes with superinfection or significant fibrous sequelae. CONCLUSIONS: Pleural effusions of TB origin are a reality more and more present due to the recrudescence of pulmonary TB in the last decades. Their presence should be suspected if faced to a unilateral pleural effusion with free-flowing fluid occurred almost often to a man of any age from youth to elderly.

Toxicity and health impact of nanoparticles. Basic biology and clinical perspective.

Stroke has limited restorative treatment options. In search of new therapeutic strategies for the ischemic brain, cell-based therapies offered new hope, which has been, in the meanwhile, converted into a more realistic approach recognizing difficulties related to unfavorable environments causing low survival rates of transplanted neuronal precursors. Stem cell therapies are based on the transplantation of neuronal precursor cells (NPCs), adult stem cells propagated in cell culture or inducible pluripotent cells (iPSCs) obtained from patients and trans-differentiated into neural cells. Of these, autologous iPSCs have the advantage to be used in stroke patients because they do not raise ethical concerns and the risk of graft rejection is low. However, the use of stem cells for stroke therapy in humans has to take into account many factors including, dosage, route of administration, toxicity and side effects. For example, nanoparticles (NPs) may increase the efficacy of drugs and therapeutic cells delivery to the diseased brain. Medication dosages are generally determined by clinical trials done in relatively young, healthy people. However, in vivo and clinical data evaluating the toxic effects of NPs on neural cells are still scarce especially in the aged brain, which has a decreased homeostatic capacity and a reduced ability to cope with internal and environmental stress, as compared to the young brain. Previous studies in rodents indicate that aging along with neurodegenerative diseases may promote a proinflammatory state and leads to the development of gliosis in the aged brains. On the other hand, the nonspecific interaction between the shell of NPs and brain proteins leads to the adsorption of opsonins on their surface, forming the so-called "corona", thereby becoming ideal candidates to attract phagocytic microglia resulting in NPs engulfment and thus exacerbating neuronal death. Therefore, when designing NPs for clinical use, it should be considered that their systemic administration is associated with potential risks, especially in the aged subjects. Recently, NPs have been shown in recent years to play a crucial role in cell signaling processes involved in stroke recovery. Extracellular vesicles (EVs) are secreted by virtually all type of cells in the body and have been shown to reflect the physiological and metabolic status of the host cells. Thus, understanding the disease-specific contents of EVs would enable the discovery of novel predictive biomarkers.

Study of antimicrobial effects of functionalized silver nanoparticles.

In recent decades, the study of nanoparticles (NPs) has gained a great scientific interest, due to a wide range of potential applications, in different fields: electronic, optical and biomedical. Some of the most studied effects of NPs are antibacterial ones, because the large, sometimes unjustified and uncontrolled administration of antibiotics has led to the emergence of multidrug-resistant (MDR) bacterial strains. In our study, starting from silver nitrate (AgNO3), we made approximately 30 nm spherical AgNPs that were coated with a thin layer of ethylene glycol (EG) or EG and polyvinylpyrrolidone (PVP). The microbial culture study showed that AgNPs have antibacterial effects, depending on the dose of the NPs and the type of bacteria.

Osteoraticular Tuberculosis-Brief Review of Clinical Morphological and Therapeutic Profiles.

Osteoarticular tuberculosis (OATB) is a rare form of tuberculosis (TB) whose incidence rose significantly nowadays especially in the underdeveloped countries. The main risk factors predisposing to this new challenge for the medical system are the Human Immunodeficiency Virus (HIV) epidemic, the migration from TB endemic areas and the development of drug and multidrug-resistant strains of Mycobacterium tuberculosis (Mt). The disease affects both genders and any age group although the distribution depending on gender is controversial and that depending on age has a bimodal pattern. In most cases the initial focus is elsewhere in the organism and the most frequent pathway of dissemination is lympho-haematogenous. The clinical picture includes local symptoms as pain, tenderness and limitation of motion, with some particularities depending on the segment of the osteoarticular system involved, sometimes accompanying systemic symptoms specific for TB and other specific clinical signs as cold abscesses and sinuses. The radiographic features are not specific, CT demonstrates abnormalities earlier than plain radiography and MRI is superior to plain radiographs in showing the extent of extraskeletal involvement. Both CT and MRI can be used in patient follow-up to evaluate responses to therapy. TBhas been reported in all bones of the body, the various sites including the spine (most often involved) and extraspinal sites (arthritis, osteomyelitis and tenosynovitis and bursitis). Two basic types of disease patterns could be present: the granular type (most often in adults) and the caseous exudative type (most often in children) one of which being predominant. The algorithm of diagnosis includes several steps of which detection of Mt is the gold standard. The actual treatment is primarily medical, consisting of antituberculosis chemotherapy (ATT), surgical interventions being warranted only for selected cases. It is essential that clinicians know and refresh their knowledge about manifestations of OATB.