Marzena Dominiak

The influence of biocomposites containing genetically modified flax fibers on gene expression in rat skeletal muscle.

Abstract In many studies, natural flax fibers have been proven to be resistant and surgically suitable. Genetically modified flax fibers, derived from transgenic flax expressing three bacterial genes for the synthesis of poly-3-hydroxybutyric acid (PHB), have better mechanical properties than unmodified flax fibers. The aim of this study was to examine the biocompatibility of composites containing flax fibers from transgenic polyhydroxybutyrate producing (M50) and control (wt-NIKE) plants in a polylactide (PLA) matrix in rat Musculus latissimus dorsi. For this purpose, effects of biocomposites on the expression of growth factors and osteogenic differentiation, in particular the mRNA expression of vascular endothelial growth factor, insulin like growth factor 1, insulin like growth factor 2, collagen-1, collagen-2 and myostatin, were analyzed using quantitative RT-PCR. The biocomposites did not show any inflammation response after subcutaneous insertion. The results following subcutaneous insertion of PLA alone and PLA-M50 showed no significant changes on the gene expression of all tested genes, whereas PLA-wt-NIKE reduced the mRNA amount of myostatin, VEGFA and IGF2, respectively. It can be asserted that modified flax membranes with PHB and other organic substances have a good biocompatibility to the muscle and they do not disrupt the muscle function. Furthermore, composites from transgenic flax plants producing PHB did not differ from composites of non-transgenic flax plants.

The clinical efficacy of primary culture of human fibroblasts in gingival augmentation procedures-a preliminary report.

The treatment of mucogingival problems is one of the main objectives of periodontal treatment. The insufficient or absent gingival attachment increases the risk of development of gingival recessions. Multiple gingival augmentation techniques of varying level of success are known. The aim of this study has been to clinically and histologically evaluate the integration process of scaffolds composed of primary human fibroblasts derived from keratinized gingiva on collagenous carriers. Ten patients exhibiting a mucogingival problem and gingival inflammation of the related teeth were included in the study. In total, 34 teeth in the anterior part of the maxilla and the mandible underwent treatment. Clinically, over a 6 month period of observation, a significant decrease in the distance from cemento-enamel junction to mucogingival junction (CEJ-MGJ) was revealed. Histologically, mature connective tissue covered by keratinized epithelium was found after 12 weeks. No specimens revealed an inflammatory response. A complete clinical healing was observed after 2 weeks in eight patients [early healing index (EHI)=I]. The results of clinical evaluation indicate that the method of primary culture of human fibroblasts on a collagenous carrier for gingival augmentation is an esthetic and effective method of mucogingival complex repair. The scaffolds were substituted and completely re-epithelialized within 12 weeks according to histologic results.

New Perspectives in the Diagnostic of Gingival Recession

Gingival recession (GR) is a common clinical situation observed in patient populations regardless of their age and ethnicity. It has been estimated that over 60% of the human population has gingival recession. It is the final effect of the interaction of multiple etiological factors. Identification and definition of the range of influence is often not possible, with the result that new methods for testing and elimination of potential etiological factors are still being sought. The aim of this study is to present the etiopathogenesis of gingival recessions with regard to the analysis of morphological and functional factors. For the assessment of the bone factors, we will describe the new cephalometric method for measuring sagital width of the bone in the central incisors area, places when GR are most commonly observed. Also, a review will be presented of modern methods of treatment; in particular classes recessions; usage substitute of autogenous tissue will be emphasized--collagen matrix, and primary culture fibroblasts on collagen net.

Osteogenic capacity of transgenic flax scaffolds

Abstract The modification of flax fibers to create biologically active dressings is of undoubted scientific and practical interest. Flax fibers, derived from transgenic flax expressing three bacterial genes for the synthesis of poly-3-hydroxybutyric acid (PHB), have better mechanical properties than unmodified flax fibers; do not show any inflammation response after subcutaneous insertion; and have a good in vitro and in vivo biocompatibility. The aim of this study was to examine the applicability of composites containing flax fibers of genetically modified (M50) or non-modified (wt-Nike) flax within a polylactide (PLA) matrix for bone regeneration. For this, the mRNA expression of genes coding for growth factors (insulin-like growth factor IGF1, IGF2, vascular endothelial growth factor), for osteogenic differentiation (alkaline phosphatase, osteocalcin, Runx2, Phex, type 1 and type 2 collagen), and for bone resorption markers [matrix metalloproteinase 8 (MMP8), acid phosphatase type 5] were analyzed using quantitative real-time polymerase chain reaction. We found a significant elevated mRNA expression of IGF1 with PLA and PLA-wt-Nike composites. The mRNA amount of MMP8 and osteocalcin was significantly decreased in all biocomposite-treated cranial tissue samples compared to controls, whereas the expression of all other tested transcripts did not show any differences. It is assumed that both flax composites are able to stimulate bone regeneration, but composites from transgenic flax plants producing PHB showed faster bone regeneration than composites of non-transgenic flax plants. The application of these linen membranes for bone tissue engineering should be proved in further studies.

Evaluation of healing processes of intraosseous defects with and without guided bone regeneration and platelet rich plasma. An animal study

BACKGROUND In most cases, the natural healing of intrabony defects only leads to restoration of tissue continuity without differentiation and function. However, repair is not regarded to be an optimal treatment method, as confirmed in many clinical cases. Thus it is important to choose a surgical procedure which makes it possible to achieve restitution ad integrum of the bone structure. The choice of the GBR technique is crucial, in terms of the clinical conditions and limitations resulting from the use of a particular material. OBJECTIVE The objective of this study has been the analysis of effectiveness of selected surgical treatment techniques of intrabony defects in rabbits. MATERIALS AND METHODS Research was conducted on 36 white rabbits. The operation technique was a criterion of division into 3 groups: BG/BOC (Bio-Oss Collagen(®)+Bio-Gide Perio(®)), BOC/PRP (Bio-Oss Collagen(®)+PRP), C (control group). Qualitative and quantitative histopathological evaluation was carried out after 1, 3, 6 and 12 months. RESULTS The highest value of the bone surface area 31.9% (SD 1.8) was achieved in BOC/BG group three months after the implantation, while the lowest was revealed in C - group - 12.5% (SD 1.32) one month following the procedure. CONCLUSIONS Upon quantitative histological assessment, the bone tissue presented the most intensive osteogenesis within one month from the application of BOC/PRP, whereas this was observed after the application of BOC/BG in later stages. The application of two regenerative methods influenced the rate, quality and overall treatment of intraosseus defects.

A silver carp skin derived collagen in bone defect treatment-A histological study in a rat model.

In recent years, there has been increasing interest in elaboration of novel therapeutic strategies, such as the use of the marine collagen products. Biochemical properties of marine collagen are different from those of mammalian collagen; e.g., its extremely high solubility in diluted acid. Extracts produced using low temperature techniques contain a number of small proteins and collagen with preserved triple helix structure. The aim of the study was to evaluate the influence of a new marine product Collgel® obtained with a unique method from a silver carp (Hypophthalmichthys molitrix) on bone defect healing in a rat study. For this purpose bone defects with diameters of 5mm were created in 15 animals and subsequently filled with Collgel combined with another commercially available material. Samples were processed for histological evaluation and a Micro-CT study was performed. Histological analysis showed new bone formation in all groups after 8 weeks. The bone formation was significantly increased in treated bone lesions compared to untreated bone tissue. However no significant difference was noted between the healing of the defects filled with xenogenic bovine derived bone substitute alone and xenogenic, bovine derived bone substitute combined with a marine delivered collagen. Finding from the histological examination was confirmed in a Micro-CT study. The study has shown that the new marine product can be used instead of conventional porcine or bovine collagen membranes in guided bone regeneration.

Bone substitution materials on the basis of BONITmatrix® up-regulate mRNA expression of IGF1 and Col1a1

The aim of this study was to investigate the effects of BONITmatrix(®) and OSSA NOVA on the expression of growth factors and osteogenic differentiation. For this purpose, the mRNA expression of VEGF, IGF1, IGF2, collagen-1, collagen-2 and MMP8 was analysed in surgically created defects on the crania of adult male rats. Cranial samples were collected after implantation of BONITmatrix(®) or OSSA NOVA scaffolds for 4 weeks and determinations of gene expression were performed by quantitative RT-PCR. Real-time RT-PCR analyses showed a significantly higher expression of IGF1 in both groups treated with BONITmatrix(®) and OSSA NOVA compared to untreated controls, whereas type I collagen mRNA expression only increased in BONITmatrix(®) treated rats compared to controls. No changes in transcript expression of IGF2, VEGF, collagen-2 and MMP8 were detectable between the analysed groups. In conclusion, BONITmatrix(®) and OSSA NOVA stimulate the expression of growth factor IGF1, but only the granular dosage form is able to stimulate osteoblast differentiation.

New nano-hydroxyapatite in bone defect regeneration: A histological study in rats

Many types of bone substitute materials are available on the market. Researchers are refining new bone substitutes to make them comparable to autologous grafting materials in treatment of bone defects. The purpose of the study was to evaluate the osseoconductive potential and bone defect regeneration in rat calvaria bone defects treated with new synthetic nano-hydroxyapatite. The study was performed on 30 rats divided into 5 equal groups. New preproduction of experimental nano-hydroxyapatite material by NanoSynHap (Poznań, Poland) was tested and compared with commercially available materials. Five mm critical size defects were created and filled with the following bone grafting materials: 1) Geistlich Bio-Oss®; 2) nano-hydroxyapatite+β-TCP; 3) nano-hydroxyapatite; 4) nano-hydroxyapatite+collagen membrane. The last group served as controls without any augmentation. Bone samples from calvaria were harvested for histological and micro-ct evaluation after 8 weeks. New bone formation was observed in all groups. Histomorphometric analysis revealed an amount of regenerated bone between 34.2 and 44.4% in treated bone defects, whereas only 13.0% regenerated bone was found in controls. Interestingly, in group 3, no significant particles of the nano-HA material were found. In contrast, residual bone substitute material could be detected in all other test groups. Micro-CT study confirmed the results of the histological examinations. The new nano-hydroxyapatite provides comparable results to other grafts in the field of bone regeneration.

Comparison of surface modified zirconia implants with commercially available zirconium and titanium implants: a histological study in pigs.

Introduction:New biomaterials and their various surface modifications should undergo in vitro and in vivo evaluation before clinical trials. The objective of our in vivo study was to evaluate the biocompatibility of newly created zirconium implant surfaces after implantation in the lower jaw of pigs and compare the osseointegration of these dental implants with commercially available zirconium and titanium implants. Materials and Methods:After a healing period of 12 weeks, a histological analysis of the soft and hard tissues and a histomorphometric analysis of the bone-implant contact (BIC) were performed. Results:The implant surfaces showed an intimate connection to the adjacent bone for all tested implants. The 3 newly created zirconium implant surfaces achieved a BIC of 45% on average in comparison with a BIC of 56% from the reference zirconium implants and 35% from titanium implants. Furthermore, the new zirconium implants had a better attachment to gingival and bone tissues in the range of implant necks as compared with the reference implants. Conclusion:The results suggest that the new implants comparably osseointegrate within the healing period, and they have a good in vivo biocompatibility.

Use of primary culture of human fibroblasts in gingiva augmentation procedure

Abstract Background: The aim of this study was to assess gingival aesthetic after usage of an own method of primary culture of human fibroblasts derived from the connective tissue of oral cavity keratinized gingiva on collagenous carrier in gingival augmentation procedures. Materials and methods: Procedures were performed on 10 patients (7 females, 3 males) aged 18–35 years. In total, 34 teeth in the anterior part of the maxilla and the mandible underwent treatment. The protocol consisted of (1) preparing the patient for tissue biopsy, (2) biopsy of keratinized tissue, (3) laboratory tissue culture, (4) application of expanded cells into the recipient site, and (5) post-procedure management. Aesthetic index, pocket depth (PD), and plaque (PI1) and after surgery complications were examined. Results: There was post-procedure aesthetic improvement in all 34 cases compared with the pre-procedure condition (grade 1), and furthermore a significant decrease in PD and PI1 were revealed. Conclusion: Use of own method of primary culture of human fibroblasts on a collagenous carrier for gingival augmentation is an aesthetic method of mucogingival complex repair.