3D Baskılı PCL-HA İskelelerde Doluluk Oranının Biyoçözünürlüğe Etkisi

Abstract

Kemik doku mühendisliğinde iskele mimarisi, hem mekanik destek sağlamak hem de fizyolojik koşullar altında bozunma davranışını düzenlemek açısından çift yönlü bir rol üstlenmektedir. Biyobozunur ve biyouyumlu bir polimer olan polikaprolakton (PCL), iskele üretiminde yaygın olarak kullanılmakta; ancak sınırlı biyolojik aktivitesi nedeniyle, hidroksiapatit (HA) gibi biyoseramiklerle takviye edilmesi gerekmektedir. PCL-HA kompozitleri, hem mekanik bütünlük hem de osteokondüktif potansiyel sunmaktadır. Önceki çalışmalar çeşitli parametrelerin etkilerini incelemiş olsa da, FDM (eriyik yığma modelleme) yöntemiyle kolayca ayarlanabilen doluluk oranının iskele bozunması üzerindeki özgül etkisi yeterince araştırılmamıştır. Bu çalışmada, %90 PCL – %10 HA içeren kompozit iskeleler, daha önce eğilme dayanımı ve yorulma direnci açısından üstün performans gösterdiği belirlenmiş tri-hegzagon dolgu deseni kullanılarak 10×10×2 mm boyutlarında üretilmiş ve %10’dan %100’e kadar artan doluluk oranlarıyla 10 gruba ayrılmıştır. Numuneler, 37 °C'de yapay vücut sıvısında (SBF) 2, 4 ve 8 hafta süreyle inkübe edilmiştir. Bozunma, kütle kaybı ölçümleri ile değerlendirilmiş; ayrıca SEM, EDX ve FTIR analizleri ile morfolojik ve kimyasal değişiklikler karakterize edilmiştir. Sonuçlar, düşük doluluk oranlarının yüzey alanı maruziyetini artırarak daha hızlı bozunmaya neden olduğunu; bu durumun daha yüksek kütle kaybı ve yüzey erozyonuyla kendini gösterdiğini ortaya koymuştur. SEM görüntüleri morfolojik bozulmayı gösterirken, EDX ve FTIR analizleri ise polimer matrisin hidrolizi ve HA fazının kısmi çözünmesini doğrulamıştır. Bu bulgular, doluluk oranının kontrollü iskele bozunması tasarımı açısından kritik bir parametre olduğunu ortaya koymakta ve PCL-HA kompozitlerinin kişiselleştirilmiş kemik doku mühendisliği uygulamaları için esnek bir platform sunduğunu göstermektedir.

Keywords

• kemik doku mühendisliği
• hidroksiapatit
• polikaprolakton
• dolgu yoğunluğu
• biyoçözünürlük

Effect of Filling Rate on Biodegradability in 3D Printed PCL-HA Scaffolds

Abstract

In bone tissue engineering, scaffold architecture serves a dual function by providing mechanical support and regulating degradation behavior under physiological conditions. Polycaprolactone (PCL), a biodegradable and biocompatible polymer, is widely used in scaffold fabrication; however, due to its limited biological activity, it is often reinforced with bioactive ceramics such as hydroxyapatite (HA). PCL-HA composites offer both structural integrity and osteoconductive potential. While previous studies have investigated various parameters influencing scaffold performance, the specific role of infill density-an easily tunable parameter in fused deposition modeling (FDM)-on degradation kinetics remains underexplored. In this study, scaffolds composed of 90% PCL and 10% HA were fabricated with a tri-hexagon infill pattern, previously shown to enhance mechanical properties, especially in flexural and fatigue strength. The scaffolds were printed as flat plates (10×10×2 mm) and divided into ten experimental groups with infill densities ranging from 10% to 100%. All samples were incubated in Simulated Body Fluid (SBF) at 37 °C for 2, 4, and 8 weeks. Scaffold degradation was assessed by measuring mass loss and further characterized via SEM, EDX, and FTIR analyses. The results demonstrated that lower infill densities led to significantly faster degradation due to increased surface area exposure, resulting in more pronounced mass loss and surface erosion. SEM imaging confirmed morphological degradation, while EDX and FTIR analyses revealed chemical changes associated with polymer breakdown and partial dissolution of the HA phase. These findings highlight the critical role of infill density in modulating scaffold biodegradability and suggest that tri-hexagon patterned PCL-HA scaffolds offer a versatile design strategy for customized bone tissue engineering applications.

Keywords

• bone tissue engineering
• hydroxyapatite
• polycaprolactone
• infill density
• biodegradability

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