Degradation of poly(l-lactide) under KrF excimer laser treatment

Stępak, Bogusz; Antończak, Arkadiusz J.; Szustakiewicz, Konrad; Kozioł, Paweł; Abramski, Krzysztof M.

doi:10.1016/j.polymdegradstab.2014.08.028

Cited by 30 publications

(11 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The C1s and O1s spectra obtained by XPS at grooves showed minor changes on the C:O ratio and the relative intensity of the C–O, O–C=O, and C=O components with respect to the not machined surface (Figure 3). The high C:O ratio measured on the not machined PLLA surface in comparison with the theoretical value has already been observed by other authors, connecting this finding to the sensitivity of obtained ratio to the take-off angle at which photoelectrons are recorded as well as the segregation of methyl groups at the surface [32,33]. The C:O ratio in the grooved area is very similar to the stochiometric ratio, indicating that no photo-oxidation occurred, as has been observed when femtosecond laser ablation is applied on PLA [34].…”

Section: Discussionsupporting

confidence: 78%

Laser Surface Microstructuring of a Bio-Resorbable Polymer to Anchor Stem Cells, Control Adipocyte Morphology, and Promote Osteogenesis

Ortiz

Aurrekoetxea-Rodríguez

Rommel

et al. 2018

Polymers

View full text Add to dashboard Cite

New strategies in regenerative medicine include the implantation of stem cells cultured in bio-resorbable polymeric scaffolds to restore the tissue function and be absorbed by the body after wound healing. This requires the development of appropriate micro-technologies for manufacturing of functional scaffolds with controlled surface properties to induce a specific cell behavior. The present report focuses on the effect of substrate topography on the behavior of human mesenchymal stem cells (MSCs) before and after co-differentiation into adipocytes and osteoblasts. Picosecond laser micromachining technology (PLM) was applied on poly (L-lactide) (PLLA), to generate different microstructures (microgrooves and microcavities) for investigating cell shape, orientation, and MSCs co-differentiation. Under certain surface topographical conditions, MSCs modify their shape to anchor at specific groove locations. Upon MSCs differentiation, adipocytes respond to changes in substrate height and depth by adapting the intracellular distribution of their lipid vacuoles to the imposed physical constraints. In addition, topography alone seems to produce a modest, but significant, increase of stem cell differentiation to osteoblasts. These findings show that PLM can be applied as a high-efficient technology to directly and precisely manufacture 3D microstructures that guide cell shape, control adipocyte morphology, and induce osteogenesis without the need of specific biochemical functionalization.

show abstract

Section: Discussionsupporting

confidence: 78%

Laser Surface Microstructuring of a Bio-Resorbable Polymer to Anchor Stem Cells, Control Adipocyte Morphology, and Promote Osteogenesis

Ortiz

Aurrekoetxea-Rodríguez

Rommel

et al. 2018

Polymers

View full text Add to dashboard Cite

show abstract

“…The ATR measurements of the samples directly after laser treatment, before water immersion, on the top and rear sides showed no explicit signs of degradation of the material in form of new IR absorption bands at 811, 990, 1410 cm −1 (-CH=CH 2 ) that were observed e.g. in case of CO 2 laser modification 24 . The differences between ATR spectra of samples modified by 1030 nm are visible after hydrolytic degradation experiment.…”

Section: Discussionmentioning

confidence: 85%

“…The thickness of the samples was 420 μm. The molecular weight of the polymer sheet was determined in previous studies where the samples were prepared according to the same procedure: M n = 247 500 g/mol, M w = 493 400 g/mol, PDI = 2.0 23,24 . The values are expressed according to polystyrene standards.…”

Section: Methodsmentioning

confidence: 99%

Diverse nature of femtosecond laser ablation of poly(L-lactide) and the influence of filamentation on the polymer crystallization behaviour

Stępak

Gazińska

Nejbauer

et al. 2019

Sci Rep

View full text Add to dashboard Cite

Over the past few years we have witnessed growing interest in ultrafast laser micromachining of bioresorbable polymers for fabrication of medical implants and surface modification. In this paper we show that surface structuring of poly(L-lactide) with 300 fs laser pulses at 515 and 1030 nm wavelength leads to formation of defects inside the polymer as a result of laser beam filamentation. Filament-induced channels have diameter around 1 μm and length of hundreds of micrometers. SEM images of microchannels cross-sections are presented. The influence of wavelength and pulse spacing on bulk modification extent was investigated and parameters limiting filamentation were determined. We show that filamentation can be used for controlling properties of PLLA. The presence of filament-induced modifications such as empty microchannels and pressure wave-induced stress lead to increased ability of polymer to crystallize at lower temperature. Crystallization behaviour and crystal morphology after laser treatment was investigated in details using different analytical techniques such as WAXD, DSC and FTIR/ATR. Hydrolytic degradation experiment was performed. Presented method can be applied for controllable, spatially distributed modification of polymer crystallinity, crystalline phase structure and hydrolytic degradation profile.

show abstract

“…As a result of laser treatment, the polylactide undergoes various changes. Stepak et al [21] pointed out that an unhomogenized KrF laser beam (above the ablation threshold) can cause considerable degradation in semicrystalline poly(l-lactic acid) (PLLA), which shows in the reduction of molecular weight measured with a GPC test, and the increase of polydispersity. They also showed that as a result of the reduction of molecular weight, transition temperatures, such as glass transition temperature, cold crystallization temperature and crystalline melting temperature decrease.…”

Section: A C C E P T E D Accepted Manuscriptmentioning

confidence: 99%

Accelerated photodegradation of poly(lactic acid) with weathering test chamber and laser exposure – A comparative study

et al. 2019

View full text Add to dashboard Cite

This study presents the comparative study of two different accelerated aging methods of poly(D-,L-lactide acid) (PLA). One is the well-known and widely used accelerated weathering chamber. The other procedure is photodegradation with a homogenized laser beam, which has not been used for the artificial aging of biopolymers so far. The film sample was artificially aged with a xenon test chamber for 200 hours, with an acceleration factor of approximately 7:1. We also performed a comparative artificial aging test using a krypton-fluoride (KrF) excimer laser in a way that the amount of energy transferred by the laser is the same as the energy transferred by the xenon lamp; the acceleration factor of the laser is higher than 42000:1. The resulting two types of photodegraded film products were compared and broadly characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), gel permeation chromatography (GPC) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR); the goal was to create comparison and possible conformity between the two methods to achieve higher acceleration factor for accelerated aging.

show abstract

Degradation of poly(l-lactide) under KrF excimer laser treatment

Cited by 30 publications

References 41 publications

Laser Surface Microstructuring of a Bio-Resorbable Polymer to Anchor Stem Cells, Control Adipocyte Morphology, and Promote Osteogenesis

Laser Surface Microstructuring of a Bio-Resorbable Polymer to Anchor Stem Cells, Control Adipocyte Morphology, and Promote Osteogenesis

Diverse nature of femtosecond laser ablation of poly(L-lactide) and the influence of filamentation on the polymer crystallization behaviour

Accelerated photodegradation of poly(lactic acid) with weathering test chamber and laser exposure – A comparative study

Contact Info

Product

Resources

About