Doku mühendisliği uygulamalarında, kimyasal yapı, pürüzlülük, hidrofiliklik, yüklü grupların dağı... more Doku mühendisliği uygulamalarında, kimyasal yapı, pürüzlülük, hidrofiliklik, yüklü grupların dağılımı gibi faktörler hücre yapışmasını ve hücre çoğalmasını etkileyen faktörlerdendir. Oksijen plazma kütlesel özellikleri etkilemeksizin yüzeyde değişikliklere yol açan bir tekniktir. Bu çalışmada, poly(D,L-lactide-co-glycolide) (PLGA) filmleri çözücü uçurma yöntemiyle hazırlanmış ve gücü 20 watts (W) ve 300 watts (W) arasında değişen oksijen plazmayla modifiye edilmiştir. Oksijen plazma uygulaması sonucu kimyasal yapı, morfoloji ve yüzey serbest enerji (SFE) değişimleri, kimyasal analiz için elektron spektroskopisi (ESCA), atomik kuvvet mikroskopisi (AFM) ve temas açısı ölçümüyle araştırılmıştır. Örneklerin hücre-malzeme ilişkisi 3T3 fibroblast hücre hattı kullanılarak hücre kültürü testleriyle değerlendirilmiştir. Plazma gücü 20 W'dan, 300'a çıkarıldığında, yüzeydeki oksijen miktarının (ESCA analiziyle) 100 W'a kadar yükseldiği, daha sonra ise yüzeyde oluşan çapraz bağlar nedeniyle bu miktarın düştüğü gözlenmiştir. Yüzey pürüzlülüğü (AFM analiziyle) ve hidrofilikliliği (temas açısı ölçümüyle) artan plazma gücüne paralel olarak artmıştır. Harmonik ortalama, Geometrik ortalama ve Asit Baz metotlarına göre, SFE değerleri artan plazma gücüyle artmıştır. Malzeme-hücre etkileşimi çalışmaları sonuçları, oksijen plazma modifikasyonunun PLGA filmleri üzerindeki hücre yapışmasını ve hücre çoğalmasını artırdığını gözlemlenmiştir.
Turkish Bulletin of Hygiene and Experimental Biology
ÖZET Amaç: Bu çalışmanın amacı konakçı bölgede enfeksiyonu tedavi etmek amacıyla medikal alanda k... more ÖZET Amaç: Bu çalışmanın amacı konakçı bölgede enfeksiyonu tedavi etmek amacıyla medikal alanda kullanılabilecek kontrollü salım sistemi hazırlamaktır. Yöntem: Mikro katmanlı filmler çözelti döküm metodu ile hazırlanmıştır. Üç katmanlı filmler kitosan (CHI), jelatin (GEL) ve aljinat (ALG) kullanılarak aljinat tabakasına ceftriaxone sodyum (CS) yüklenmiş, ayrıca kontrol grubu için ilaç yüklenmemiş olarak hazırlanmış ve sırasıyla CHI /ALG/CHI ve CHI-GEL/ALG-CS/CHI-GEL olarak kodlandırılmıştır. Bütün filmler glutaraldehit (GA) buharına farklı süre boyunca (2 h, 10 h veya 24 h) tabi tutularak çapraz bağlanmıştır. Filmlerin mekanik özellikleri ve CS'nin filmlerden salım kinetikleri üç farklı pH şartlarında (pH 5,5, 7,4, ve 10,0) incelenmiştir. Salınan CS'nin Escherichia coli'ye karşı antibakteriyel etkinliği agar spot yöntemiyle test edilmiştir. Bulgular: Sonuçlar üç-katmanlı film yapılarının üst ve alt katmanında GEL varlığının filmlerin kırılganlığı önlediğini ve mekanik dayanımını arttırdığını, ancak orta katmanda CS varlığının mekanik özellikleri düşürdüğünü göstermiştir. Filmlerin GA ile çapraz bağlanması CS'nin salımında anlamlı bir etki göstermemiştir, ancak kitosanın aljinat ve CS ile etkileşiminden dolayı ilaç ABSTRACT Objective: The objective of this study was to prepare a controlled release system, which could be used in medical applications in order to treat infections at the host region. Methods: Microlayer films were prepared via solvent casting method. Films with 3-layers were prepared by using chitosan (CHI), gelatin (GEL) and alginate (ALG) in the form of CHI /ALG/CHI and CHI-GEL /ALG/CHI-GEL with or without ceftriaxone sodium (CS) which is loaded in the middle ALG layer. All films were crosslinked by exposing them to glutaraldehyde (GA) vapor for different (2 h, 10 h or 24 h) durations. Mechanical properties of the films and release kinetics of CS at three different pH conditions (pH 5.5, 7.4, and 10.0) were investigated. The antibacterial efficiency of the released CS against Escherichia coli was examined via agar spot test. Results: The results indicated that the presence of GEL in the upper and lower layers of the 3-layer construct prevented fragility and increased the mechanical strength of the films, whereas the presence of CS in the middle layer caused decrease in the mechanical properties. Crosslinking with GA did not demonstrate a significant effect on the release profile of CS, but Kızıltay A, Gündogan Z, Erel-Göktepe İ, Hasırcı N. Multilayer polymeric films for controlled release of ceftriaxone sodium. Turk Hij Den Biyol Derg, 2019; 76(3): 303-312 Makale Dili "İngilizce"/Article Language "English"
Journal of biomaterials science. Polymer edition, Jan 20, 2017
Biodegradable polymers have met withan increasing demand in medical usage over the last decades. ... more Biodegradable polymers have met withan increasing demand in medical usage over the last decades. One of such polymers is poly(ε-caprolactone) (PCL), whichis a polyester that has been widely used in tissue engineering field for its availability, relatively inexpensive price and suitability for modification. Its chemical and biological properties, physicochemical state, degradability and mechanical strengthcan be adjusted, and therefore,it can be usedunderharsh mechanical, physical and chemical conditions without significant loss of its properties. Degradation time of PCL is quite long, thus it is used mainly in the replacement of hard tissues inthe body where healing also takes an extended period of time. It is also used at load-bearing tissues of the body by enhancing its stiffness. However, due to its tailorability, use of PCL is not restricted to one type of tissueand it can be extended to engineering of soft tissues by decreasing its molecular weight and degradation time. This re...
Scaffolds produced for tissue engineering applications are proven to be promising alternatives to... more Scaffolds produced for tissue engineering applications are proven to be promising alternatives to be used in healing and regeneration of injured tissues and organs. In this study, porous and fibrous poly(ε-caprolactone) (PCL) scaffolds were prepared by wet spinning technique and modified by addition of tricalcium phosphate (TCP) and by immobilizing gelatin onto fibers. Meanwhile, gelatin microspheres carrying Ceftriaxone sodium (CS), a model antibiotic, were added onto the scaffolds and antimicrobial activity of CS was investigated against Escherichia coli (E. coli), a model gram-negative bacterium. TCP and gelatin were added to enhance mechanical properties while directing the scaffold towards osteogenic infrastructure and to increase hydrophilicity by activating cell attachment via protein molecules, respectively. Modifications with TCP and gelatin enhanced the compression modulus by about 70%, and attachment of Saos-2 cells by 60%, respectively. Release of the antibiotic demonstrated effective antimicrobial activity against E. coli. The bioactive scaffolds were shown to be good candidates for bone tissue engineering applications.
Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones... more Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones are prepared from poly (methylmethacrylate) (PMMA). In orthopaedic surgery bone cements are used as filling agents for the treatment of damaged tissues and they are used to stabilize the prosthesis by providing the mechanical interlock between bone and metal during the use of metal prothesis
The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones... more Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones are prepared from poly (methylmethacrylate) (PMMA). In orthopaedic surgery bone cements are used as filling agents for the treatment of damaged tissues and they are used to stabilize the prosthesis by providing the mechanical interlock between bone and metal during the use of metal prothesis
Journal of Biomaterials and Tissue Engineering, 2012
ABSTRACT In this study, biodegradable, biocompatible, thermoplastic poly(ester-urethane) (PEU) wa... more ABSTRACT In this study, biodegradable, biocompatible, thermoplastic poly(ester-urethane) (PEU) was synthesized from L-lysine diisocyanate (LDI) and polycaprolactone diol (PCL), and two dimensional (2D) film structures were molded either as smooth or micropatterned forms. Both types were coated with fibrinogen (Fn) to compare the effects of micro patterns and presence of fibrinogen, on the cell behaviour. The films were highly elastic and stable in aqueous media while biodegradable in the presence of lipase. Cell culture studies with rat bone marrow stem cells (BMSCs) indicated that polymer was suitable for cell attachment and proliferation and Fn coated surfaces had the highest value where the cells oriented themselves along the micropatterns. In general, formation of micropatterns did not demonstrate an effective variation in cell proliferation and osteoblastic differentiation, but the Fn coating did. The results indicated that the synthesized lysine based poly(ester-urethane) demonstrated favorable mechanical properties, enhanced Fn adsorption and cell attachment, and therefore suitable for both soft and hard tissue applications.
Incisional hernia following laparotomy and recurrent herniation after its repair are still common... more Incisional hernia following laparotomy and recurrent herniation after its repair are still common problems in spite of mesh augmentation. The underlying biological mechanism may be related to collagen metabolism. Recently, some members of growth factors family have been tested in the prevention of wound failure and incisonal hernia formation. Growth factors may promote fibroblast proliferation and collagen deposition. In the present study, we searched the effects of basic fibroblast growth factor (bFGF) loaded polypropylene meshes in an incisional hernia model in rats. A total of 80 Wistar albino rats were randomly divided into five groups. A uniform surgical procedure was employed in all groups: a 5 cm skin incision was made at the midline and a full segment of the abdominal wall sized 3 x 2 cm was excised. Abdominal wall was closed with rapidly absorbable 3/0 catgut. Following this standard surgery, five different procedures were applied to the groups before closing the skin with ...
The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
grupların dağılımı gibi faktörler hücre yapışmasını ve hücre çoğalmasını etkileyen faktörlerdendi... more grupların dağılımı gibi faktörler hücre yapışmasını ve hücre çoğalmasını etkileyen faktörlerdendir. Oksijen plazma kütlesel özellikleri etkilemeksizin yüzeyde değişikliklere yol açan bir tekniktir. Bu çalışmada, poly(D,L-lactide-co-glycolide) (PLGA) filmleri çözücü uçurma yöntemiyle hazırlanmış ve gücü 20 watts (W) ve 300 watts (W) arasında değişen oksijen plazmayla modifiye edilmiştir. Oksijen plazma uygulaması sonucu kimyasal yapı, morfoloji ve yüzey serbest enerji (SFE) değişimleri, kimyasal analiz için elektron spektroskopisi (ESCA), atomik kuvvet mikroskopisi (AFM) ve temas açısı ölçümüyle araştırılmıştır. Örneklerin hücre-malzeme ilişkisi 3T3 fibroblast hücre hattı kullanılarak hücre kültürü testleriyle değerlendirilmiştir. Plazma gücü 20 W'dan, 300'a çıkarıldığında, yüzeydeki oksijen miktarının (ESCA analiziyle) 100 W'a kadar yükseldiği, daha sonra ise yüzeyde oluşan çapraz bağlar nedeniyle bu miktarın düştüğü gözlenmiştir. Yüzey pürüzlülüğü (AFM analiziyle) ve hidrofilikliliği (temas açısı ölçümüyle) artan plazma gücüne paralel olarak artmıştır. Harmonik ortalama, Geometrik ortalama ve Asit Baz metotlarına göre, SFE değerleri artan plazma gücüyle artmıştır. Malzeme-hücre etkileşimi çalışmaları sonuçları, oksijen plazma modifikasyonunun PLGA filmleri üzerindeki hücre yapışmasını ve hücre çoğalmasını artırdığını gözlemlenmiştir.
Previous studies have shown epidermal growth factor (EGF) facilitate peritoneal membrane healing ... more Previous studies have shown epidermal growth factor (EGF) facilitate peritoneal membrane healing by augmenting cell adhesion and migration. The objective of this study was to show the effect of sustained and local administration of EGF on peritoneal adhesion. Fourty-two rats were divided into six groups: control 7 and 14, gelatin 7 and 14, and EGF 7 and 14. Adhesions were created by scraping the cecum with mesh gause followed by application of absolute alcohol and placement of silk suture in the parietal peritoneum. The anterior walls of the intestines were covered with 5 9 5 cm unloaded, and EGF loaded gelatin films in the gelatin and EGF groups, respectively. The rats were killed on days 7 and 14 to assess the adhesion occurring, and for biochemical examination. The mean adhesion grades of EGF groups were significantly lower than in the other groups (P \ 0.008). The mean adenosine deaminase (ADA) measurements of EGF 7 group were lower than in the gelatin 7 and control 7 groups but the difference was not significant (P [ 0.008). The mean ADA measurements in the 14 days groups were as follows: control 14 \ EGF 14 \ gelatin 14 groups. The mean ADA measurements between 14 days groups did not significantly differ from each other (P [ 0.008). The mean hydroxyproline measurements did not differ among the groups (P [ 0.008). EGF decreased intestinal adhesion in our study. EGF has important roles in DNA synthesis and cell proliferation. Further studies are required to determine the exact mechanism by which EGF lowers the efficiency of intestinal adhesion.
Tranilast is an antiallergic drug that interferes with proliferation and migration of vascular sm... more Tranilast is an antiallergic drug that interferes with proliferation and migration of vascular smooth muscle cell induced by platelet-derived growth factor (PDGF) and transforming growth factor-β1 (TGF-β1). We investigated the local effect of tranilast on neointimal hyperplasia using tranilastcoated prosthetic grafts. The inner sides of the thin-walled polytetrafluoroethylene (PTFE) grafts were coated with chitosan and tranilast containing chitosan solution. Wistar albino rats (32) were used in the study. Patches (1 × 2 mm) for vascular grafts were prepared. Three groups were tested: group 1 (n = 12; tranilast coated), group 2 (n = 10; adhesive-only film-layer-coated), and group 3 (n = 10; normal ePTFE patch grafts sutured to the carotid arteries of the rats). Recipient sites of the carotid arteries were excised 4 weeks after surgery. All sections were examined histologically for graft patency, thrombus formation, and neointimal thickness. Expression of PDGF, fibroblast growth factor, and TGF-β1 on cross-sections of the neointima were evaluated by immunohistochemistry. No significant differences were found regarding mean neointimal thicknesses. PDGF and TGF-β-1 expressions were significantly lower in group 1. Although a decrease in local effect of tranilast was observed for growth factor expressions at a drug concentration of 0.05 mg/cm 2 , a significant reduction in neointimal hyperplasia was not achieved. The coating concentration of 0.05 mg/cm 2 may have been too low to produce an antiproliferative effect. Given our promising results, further studies are recommended and planned using different drug concentrations and time intervals.
The effect of the particle size of poly(methyl methacrylate) (PMMA) and the incorporation of chit... more The effect of the particle size of poly(methyl methacrylate) (PMMA) and the incorporation of chitosan (CH) on the mechanical and thermal properties and the biocompatibility of acrylic bone cements were investigated. Three groups of bone cements were prepared with different PMMA particles. Groups 1 (BC1) and 2 (BC2) contained ground and sieved PMMA with particle sizes in the ranges 50-150 lm and 1-50 lm, and group 3 (BC3) contained synthesized PMMA microspheres with a size of about 1 lm. The mechanical properties of the three groups were similar, but their curing properties were significantly affected. The presence of CH improved the mechanical and thermal properties. For the BC1 group, the compressive strength increased more than 10 MPa, and the curing temperature decreased 12 . The cement having the optimum properties (BC1) was applied to rats, where it enhanced the bone bonding ability, and bioactivity was observed.
Doku mühendisliği uygulamalarında, kimyasal yapı, pürüzlülük, hidrofiliklik, yüklü grupların dağı... more Doku mühendisliği uygulamalarında, kimyasal yapı, pürüzlülük, hidrofiliklik, yüklü grupların dağılımı gibi faktörler hücre yapışmasını ve hücre çoğalmasını etkileyen faktörlerdendir. Oksijen plazma kütlesel özellikleri etkilemeksizin yüzeyde değişikliklere yol açan bir tekniktir. Bu çalışmada, poly(D,L-lactide-co-glycolide) (PLGA) filmleri çözücü uçurma yöntemiyle hazırlanmış ve gücü 20 watts (W) ve 300 watts (W) arasında değişen oksijen plazmayla modifiye edilmiştir. Oksijen plazma uygulaması sonucu kimyasal yapı, morfoloji ve yüzey serbest enerji (SFE) değişimleri, kimyasal analiz için elektron spektroskopisi (ESCA), atomik kuvvet mikroskopisi (AFM) ve temas açısı ölçümüyle araştırılmıştır. Örneklerin hücre-malzeme ilişkisi 3T3 fibroblast hücre hattı kullanılarak hücre kültürü testleriyle değerlendirilmiştir. Plazma gücü 20 W'dan, 300'a çıkarıldığında, yüzeydeki oksijen miktarının (ESCA analiziyle) 100 W'a kadar yükseldiği, daha sonra ise yüzeyde oluşan çapraz bağlar nedeniyle bu miktarın düştüğü gözlenmiştir. Yüzey pürüzlülüğü (AFM analiziyle) ve hidrofilikliliği (temas açısı ölçümüyle) artan plazma gücüne paralel olarak artmıştır. Harmonik ortalama, Geometrik ortalama ve Asit Baz metotlarına göre, SFE değerleri artan plazma gücüyle artmıştır. Malzeme-hücre etkileşimi çalışmaları sonuçları, oksijen plazma modifikasyonunun PLGA filmleri üzerindeki hücre yapışmasını ve hücre çoğalmasını artırdığını gözlemlenmiştir.
Turkish Bulletin of Hygiene and Experimental Biology
ÖZET Amaç: Bu çalışmanın amacı konakçı bölgede enfeksiyonu tedavi etmek amacıyla medikal alanda k... more ÖZET Amaç: Bu çalışmanın amacı konakçı bölgede enfeksiyonu tedavi etmek amacıyla medikal alanda kullanılabilecek kontrollü salım sistemi hazırlamaktır. Yöntem: Mikro katmanlı filmler çözelti döküm metodu ile hazırlanmıştır. Üç katmanlı filmler kitosan (CHI), jelatin (GEL) ve aljinat (ALG) kullanılarak aljinat tabakasına ceftriaxone sodyum (CS) yüklenmiş, ayrıca kontrol grubu için ilaç yüklenmemiş olarak hazırlanmış ve sırasıyla CHI /ALG/CHI ve CHI-GEL/ALG-CS/CHI-GEL olarak kodlandırılmıştır. Bütün filmler glutaraldehit (GA) buharına farklı süre boyunca (2 h, 10 h veya 24 h) tabi tutularak çapraz bağlanmıştır. Filmlerin mekanik özellikleri ve CS'nin filmlerden salım kinetikleri üç farklı pH şartlarında (pH 5,5, 7,4, ve 10,0) incelenmiştir. Salınan CS'nin Escherichia coli'ye karşı antibakteriyel etkinliği agar spot yöntemiyle test edilmiştir. Bulgular: Sonuçlar üç-katmanlı film yapılarının üst ve alt katmanında GEL varlığının filmlerin kırılganlığı önlediğini ve mekanik dayanımını arttırdığını, ancak orta katmanda CS varlığının mekanik özellikleri düşürdüğünü göstermiştir. Filmlerin GA ile çapraz bağlanması CS'nin salımında anlamlı bir etki göstermemiştir, ancak kitosanın aljinat ve CS ile etkileşiminden dolayı ilaç ABSTRACT Objective: The objective of this study was to prepare a controlled release system, which could be used in medical applications in order to treat infections at the host region. Methods: Microlayer films were prepared via solvent casting method. Films with 3-layers were prepared by using chitosan (CHI), gelatin (GEL) and alginate (ALG) in the form of CHI /ALG/CHI and CHI-GEL /ALG/CHI-GEL with or without ceftriaxone sodium (CS) which is loaded in the middle ALG layer. All films were crosslinked by exposing them to glutaraldehyde (GA) vapor for different (2 h, 10 h or 24 h) durations. Mechanical properties of the films and release kinetics of CS at three different pH conditions (pH 5.5, 7.4, and 10.0) were investigated. The antibacterial efficiency of the released CS against Escherichia coli was examined via agar spot test. Results: The results indicated that the presence of GEL in the upper and lower layers of the 3-layer construct prevented fragility and increased the mechanical strength of the films, whereas the presence of CS in the middle layer caused decrease in the mechanical properties. Crosslinking with GA did not demonstrate a significant effect on the release profile of CS, but Kızıltay A, Gündogan Z, Erel-Göktepe İ, Hasırcı N. Multilayer polymeric films for controlled release of ceftriaxone sodium. Turk Hij Den Biyol Derg, 2019; 76(3): 303-312 Makale Dili "İngilizce"/Article Language "English"
Journal of biomaterials science. Polymer edition, Jan 20, 2017
Biodegradable polymers have met withan increasing demand in medical usage over the last decades. ... more Biodegradable polymers have met withan increasing demand in medical usage over the last decades. One of such polymers is poly(ε-caprolactone) (PCL), whichis a polyester that has been widely used in tissue engineering field for its availability, relatively inexpensive price and suitability for modification. Its chemical and biological properties, physicochemical state, degradability and mechanical strengthcan be adjusted, and therefore,it can be usedunderharsh mechanical, physical and chemical conditions without significant loss of its properties. Degradation time of PCL is quite long, thus it is used mainly in the replacement of hard tissues inthe body where healing also takes an extended period of time. It is also used at load-bearing tissues of the body by enhancing its stiffness. However, due to its tailorability, use of PCL is not restricted to one type of tissueand it can be extended to engineering of soft tissues by decreasing its molecular weight and degradation time. This re...
Scaffolds produced for tissue engineering applications are proven to be promising alternatives to... more Scaffolds produced for tissue engineering applications are proven to be promising alternatives to be used in healing and regeneration of injured tissues and organs. In this study, porous and fibrous poly(ε-caprolactone) (PCL) scaffolds were prepared by wet spinning technique and modified by addition of tricalcium phosphate (TCP) and by immobilizing gelatin onto fibers. Meanwhile, gelatin microspheres carrying Ceftriaxone sodium (CS), a model antibiotic, were added onto the scaffolds and antimicrobial activity of CS was investigated against Escherichia coli (E. coli), a model gram-negative bacterium. TCP and gelatin were added to enhance mechanical properties while directing the scaffold towards osteogenic infrastructure and to increase hydrophilicity by activating cell attachment via protein molecules, respectively. Modifications with TCP and gelatin enhanced the compression modulus by about 70%, and attachment of Saos-2 cells by 60%, respectively. Release of the antibiotic demonstrated effective antimicrobial activity against E. coli. The bioactive scaffolds were shown to be good candidates for bone tissue engineering applications.
Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones... more Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones are prepared from poly (methylmethacrylate) (PMMA). In orthopaedic surgery bone cements are used as filling agents for the treatment of damaged tissues and they are used to stabilize the prosthesis by providing the mechanical interlock between bone and metal during the use of metal prothesis
The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones... more Bone cements are used in orthopaedic surgery and dentistry, and the commonly used commercial ones are prepared from poly (methylmethacrylate) (PMMA). In orthopaedic surgery bone cements are used as filling agents for the treatment of damaged tissues and they are used to stabilize the prosthesis by providing the mechanical interlock between bone and metal during the use of metal prothesis
Journal of Biomaterials and Tissue Engineering, 2012
ABSTRACT In this study, biodegradable, biocompatible, thermoplastic poly(ester-urethane) (PEU) wa... more ABSTRACT In this study, biodegradable, biocompatible, thermoplastic poly(ester-urethane) (PEU) was synthesized from L-lysine diisocyanate (LDI) and polycaprolactone diol (PCL), and two dimensional (2D) film structures were molded either as smooth or micropatterned forms. Both types were coated with fibrinogen (Fn) to compare the effects of micro patterns and presence of fibrinogen, on the cell behaviour. The films were highly elastic and stable in aqueous media while biodegradable in the presence of lipase. Cell culture studies with rat bone marrow stem cells (BMSCs) indicated that polymer was suitable for cell attachment and proliferation and Fn coated surfaces had the highest value where the cells oriented themselves along the micropatterns. In general, formation of micropatterns did not demonstrate an effective variation in cell proliferation and osteoblastic differentiation, but the Fn coating did. The results indicated that the synthesized lysine based poly(ester-urethane) demonstrated favorable mechanical properties, enhanced Fn adsorption and cell attachment, and therefore suitable for both soft and hard tissue applications.
Incisional hernia following laparotomy and recurrent herniation after its repair are still common... more Incisional hernia following laparotomy and recurrent herniation after its repair are still common problems in spite of mesh augmentation. The underlying biological mechanism may be related to collagen metabolism. Recently, some members of growth factors family have been tested in the prevention of wound failure and incisonal hernia formation. Growth factors may promote fibroblast proliferation and collagen deposition. In the present study, we searched the effects of basic fibroblast growth factor (bFGF) loaded polypropylene meshes in an incisional hernia model in rats. A total of 80 Wistar albino rats were randomly divided into five groups. A uniform surgical procedure was employed in all groups: a 5 cm skin incision was made at the midline and a full segment of the abdominal wall sized 3 x 2 cm was excised. Abdominal wall was closed with rapidly absorbable 3/0 catgut. Following this standard surgery, five different procedures were applied to the groups before closing the skin with ...
The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
grupların dağılımı gibi faktörler hücre yapışmasını ve hücre çoğalmasını etkileyen faktörlerdendi... more grupların dağılımı gibi faktörler hücre yapışmasını ve hücre çoğalmasını etkileyen faktörlerdendir. Oksijen plazma kütlesel özellikleri etkilemeksizin yüzeyde değişikliklere yol açan bir tekniktir. Bu çalışmada, poly(D,L-lactide-co-glycolide) (PLGA) filmleri çözücü uçurma yöntemiyle hazırlanmış ve gücü 20 watts (W) ve 300 watts (W) arasında değişen oksijen plazmayla modifiye edilmiştir. Oksijen plazma uygulaması sonucu kimyasal yapı, morfoloji ve yüzey serbest enerji (SFE) değişimleri, kimyasal analiz için elektron spektroskopisi (ESCA), atomik kuvvet mikroskopisi (AFM) ve temas açısı ölçümüyle araştırılmıştır. Örneklerin hücre-malzeme ilişkisi 3T3 fibroblast hücre hattı kullanılarak hücre kültürü testleriyle değerlendirilmiştir. Plazma gücü 20 W'dan, 300'a çıkarıldığında, yüzeydeki oksijen miktarının (ESCA analiziyle) 100 W'a kadar yükseldiği, daha sonra ise yüzeyde oluşan çapraz bağlar nedeniyle bu miktarın düştüğü gözlenmiştir. Yüzey pürüzlülüğü (AFM analiziyle) ve hidrofilikliliği (temas açısı ölçümüyle) artan plazma gücüne paralel olarak artmıştır. Harmonik ortalama, Geometrik ortalama ve Asit Baz metotlarına göre, SFE değerleri artan plazma gücüyle artmıştır. Malzeme-hücre etkileşimi çalışmaları sonuçları, oksijen plazma modifikasyonunun PLGA filmleri üzerindeki hücre yapışmasını ve hücre çoğalmasını artırdığını gözlemlenmiştir.
Previous studies have shown epidermal growth factor (EGF) facilitate peritoneal membrane healing ... more Previous studies have shown epidermal growth factor (EGF) facilitate peritoneal membrane healing by augmenting cell adhesion and migration. The objective of this study was to show the effect of sustained and local administration of EGF on peritoneal adhesion. Fourty-two rats were divided into six groups: control 7 and 14, gelatin 7 and 14, and EGF 7 and 14. Adhesions were created by scraping the cecum with mesh gause followed by application of absolute alcohol and placement of silk suture in the parietal peritoneum. The anterior walls of the intestines were covered with 5 9 5 cm unloaded, and EGF loaded gelatin films in the gelatin and EGF groups, respectively. The rats were killed on days 7 and 14 to assess the adhesion occurring, and for biochemical examination. The mean adhesion grades of EGF groups were significantly lower than in the other groups (P \ 0.008). The mean adenosine deaminase (ADA) measurements of EGF 7 group were lower than in the gelatin 7 and control 7 groups but the difference was not significant (P [ 0.008). The mean ADA measurements in the 14 days groups were as follows: control 14 \ EGF 14 \ gelatin 14 groups. The mean ADA measurements between 14 days groups did not significantly differ from each other (P [ 0.008). The mean hydroxyproline measurements did not differ among the groups (P [ 0.008). EGF decreased intestinal adhesion in our study. EGF has important roles in DNA synthesis and cell proliferation. Further studies are required to determine the exact mechanism by which EGF lowers the efficiency of intestinal adhesion.
Tranilast is an antiallergic drug that interferes with proliferation and migration of vascular sm... more Tranilast is an antiallergic drug that interferes with proliferation and migration of vascular smooth muscle cell induced by platelet-derived growth factor (PDGF) and transforming growth factor-β1 (TGF-β1). We investigated the local effect of tranilast on neointimal hyperplasia using tranilastcoated prosthetic grafts. The inner sides of the thin-walled polytetrafluoroethylene (PTFE) grafts were coated with chitosan and tranilast containing chitosan solution. Wistar albino rats (32) were used in the study. Patches (1 × 2 mm) for vascular grafts were prepared. Three groups were tested: group 1 (n = 12; tranilast coated), group 2 (n = 10; adhesive-only film-layer-coated), and group 3 (n = 10; normal ePTFE patch grafts sutured to the carotid arteries of the rats). Recipient sites of the carotid arteries were excised 4 weeks after surgery. All sections were examined histologically for graft patency, thrombus formation, and neointimal thickness. Expression of PDGF, fibroblast growth factor, and TGF-β1 on cross-sections of the neointima were evaluated by immunohistochemistry. No significant differences were found regarding mean neointimal thicknesses. PDGF and TGF-β-1 expressions were significantly lower in group 1. Although a decrease in local effect of tranilast was observed for growth factor expressions at a drug concentration of 0.05 mg/cm 2 , a significant reduction in neointimal hyperplasia was not achieved. The coating concentration of 0.05 mg/cm 2 may have been too low to produce an antiproliferative effect. Given our promising results, further studies are recommended and planned using different drug concentrations and time intervals.
The effect of the particle size of poly(methyl methacrylate) (PMMA) and the incorporation of chit... more The effect of the particle size of poly(methyl methacrylate) (PMMA) and the incorporation of chitosan (CH) on the mechanical and thermal properties and the biocompatibility of acrylic bone cements were investigated. Three groups of bone cements were prepared with different PMMA particles. Groups 1 (BC1) and 2 (BC2) contained ground and sieved PMMA with particle sizes in the ranges 50-150 lm and 1-50 lm, and group 3 (BC3) contained synthesized PMMA microspheres with a size of about 1 lm. The mechanical properties of the three groups were similar, but their curing properties were significantly affected. The presence of CH improved the mechanical and thermal properties. For the BC1 group, the compressive strength increased more than 10 MPa, and the curing temperature decreased 12 . The cement having the optimum properties (BC1) was applied to rats, where it enhanced the bone bonding ability, and bioactivity was observed.
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