The isolation, analytical characterization by HPLC-UV and NMR spectroscopy, cytotoxic and antioxidant activities of baeomycesic acid from Thamnolia vermicularis var. subuliformis

The aim of this work was the analytical characterization of the β-orcinol depside, baeomycesic acid in lichens extracts. The extract of Thamnolia vermicularis var. subuliformis was analyzed by the two different methods, namely HPLC-UV and 1H NMR analysis. The results showed that baeomycesic acid was the most abundant depside in the lichens. These results could be of use for rapid identification of this metabolite in other lichen species. Besides baeomycesic acid, three depsides and one monocyclic phenolic compound were isolated from the lichen extract on the chromatographic column. The structure of baeomycesic acid was confirmed by HPLC-UV and spectroscopic methods. In addition, antioxidant and cytotoxic activities of baeomycesic acid were determined. The result of the testing showed that baeomycesic acid exhibited a moderate radical scavenging activity (IC50 = 602.10 ± 0.54 μg/mL) and good cytotoxic activity. This is the first report of detailed analytical characterization, isolation, as well as antioxidant and cytotoxic activities of baeomycesic acid from Thamnolia vermicularis. These results may be helpful in future industrial production of herbal medicines that include this important natural product

Concept and strategies of bone tissue engineering

In contemporary clinical practice bone substitutes such as implants are used in reconstructive orthopedics and maxillofacial surgery. Judging from physical and chemical properties each implant has some advantages and disadvantages. The idea of bone tissue engineering is to simulate the formation of bone to implants as carriers in combination with osteogenic cells and osteo-stimulative factors (osteoinduction). The design of the implant itself in terms of the chosen carrier with its own characteristics, the type of cells that have been implanted, the type and combination of stimulative factors play an important role in the behavior of the implanted material within a body. Tissue engineering looks promising, however a lot of obstacles have to be surmounted in order to consider it a proper alternative

HPLC analysis, antimicrobial and antioxidant activities of Daphne cneorum L.

The present study describes in vitro antimicrobial and antioxidant activities of the methanol extracts which were obtained from the leaves and twigs of the plant Daphne cneorum L. The antimicrobial activity of these extracts was tested against human pathogenic microorganisms using a minimum inhibitory concentration (MIC) values. Total phenolics and flavonoids, as well as the antioxidant activity of the extracts were determined. The two tested extracts showed good antimicrobial and antioxidant activities. The results of a high performance liquid chromatographic (HPLC) method showed that 7,8-dihydroxycoumarin is one of the most abundant secondary metabolite in the tested extracts. The results of this study clearly indicated that the extracts of D. cneorum could be used as a potential source of natural antioxidant and antimicrobial agents

Nanomaterial N-CP/DLPLG as potent1onal tissue graft in osteoreparation in combination with bone marrow cells on subcutaneous implantation model

The need for bone graft materials in osteoreparation is tremendous. Many researches have shown that calcium-phosphate bioceramics have good biocompatibility and osteoconductivity. We used nanocomposite biomaterial calcium phosphate coated with poly (dl-lactide-co-glycolide) or N-CP/DLPLG. The goal of this investigation was to examine weather N-CP/DLPLG has ability to sustain growth of bone marrow cells after subcutaneous implantation in Balb/c mice. For that purpose N-CP/DLPLG implants with and without bone marrow cells (control) were made. Implants were extracted after eight days and eight weeks. In implants loaded with bone marrow cells after eight days and eight weeks we observed fields rich in cells, angiogenesis and collagen genesis. These results showed that N-CP/DLPLG has property of tissue scaffold which sustain bone marrow cells growth and collagen production. This represents a good way for further examination of N-CP/DLPLG as potentional tissue scaffold in osteoreparation

Ectopic osteogenesis and hematopoiesis after implantantion of bone marrow cells seeded on HAP/PLLA scaffold

Bone tissue reconstruction and reparation is a big challenge in medicine. Biocomposite materials based on hidroxyapatite are widely used in reparation of bone defects. Adult bone marrow-derived stem cells may be considered in two categories: hematopoietic stem cells (HSC) from the bone marrow and mesenchymal stem cells from the bone marrow stroma (BMSC). HSC and BMSC do not only coexist in one organ, but functionally cooperate. BMSC have a critical role in the formation of hematopoietic microenvironment (HME). The aim of this study was to investigate the interactions between bone marrow cells and biocomposites based on HAp/PLLA (hidroxyapatite/poly-L-lactide) after subcutaneous implantation in Balb/c mice. In that purpose, bone marrow cells of Balb/c mice were seeded in HAp/PLLA tubes (15 mm×1,5 mm). The HAp/PLLA tubes with BMC was subcutaneously implanted with a needle into the intrascapsular region of the mouse. Implants were extracted after 2, 6 and 12 weeks. In implants after 2 and 6 weeks we found angiogenesis, collagenogenesis and new bone. Ectopic hematopoiesis was seen in implants after 12 weeks from implantation. As a good scaffold in the role of supporting osteogenesis and hematopoiesis, biocomposites HAp/PLLA can be good bone substitute materials in the bone reparation process. These results showed that the HAp/PLLA scaffold owned biological properties comparable to natural bone