scholarly journals Comparison of Different Approaches to Surface Functionalization of Biodegradable Polycaprolactone Scaffolds

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1769 ◽  
Author(s):  
Elizaveta S. Permyakova ◽  
Philipp V. Kiryukhantsev-Korneev ◽  
Kristina Yu. Gudz ◽  
Anton S. Konopatsky ◽  
Josef Polčak ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Mechanical Stability ◽  
Atmospheric Pressure Plasma ◽  
Promising Material ◽  
Bone Tissue Regeneration ◽  
Regeneration Ability ◽  
Biodegradable Poly ◽  
Plasma Copolymerization ◽  
Surface Modified

Due to their good mechanical stability compared to gelatin, collagen or polyethylene glycol nanofibers and slow degradation rate, biodegradable poly-ε-caprolactone (PCL) nanofibers are promising material as scaffolds for bone and soft-tissue engineering. Here, PCL nanofibers were prepared by the electrospinning method and then subjected to surface functionalization aimed at improving their biocompatibility and bioactivity. For surface modification, two approaches were used: (i) COOH-containing polymer was deposited on the PCL surface using atmospheric pressure plasma copolymerization of CO2 and C2H4, and (ii) PCL nanofibers were coated with multifunctional bioactive nanostructured TiCaPCON film by magnetron sputtering of TiC–CaO–Ti3POx target. To evaluate bone regeneration ability in vitro, the surface-modified PCL nanofibers were immersed in simulated body fluid (SBF, 1×) for 21 days. The results obtained indicate different osteoblastic and epithelial cell response depending on the modification method. The TiCaPCON-coated PCL nanofibers exhibited enhanced adhesion and proliferation of MC3T3-E1 cells, promoted the formation of Ca-based mineralized layer in SBF and, therefore, can be considered as promising material for bone tissue regeneration. The PCL–COOH nanofibers demonstrated improved adhesion and proliferation of IAR-2 cells, which shows their high potential for skin reparation and wound dressing.

scholarly journals The Effects of Atmospheric Pressure Argon Plasma Treated Bovine Bone Substitute on Bone Regeneration

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 790
Author(s):  
Jong-Ju Ahn ◽  
Ji-Hyun Yoo ◽  
Eun-Bin Bae ◽  
Gyoo-Cheon Kim ◽  
Jae Joon Hwang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Atmospheric Pressure ◽  
Bone Substitute ◽  
Argon Plasma ◽  
Atmospheric Pressure Plasma ◽  
Regeneration Ability ◽  
Bovine Bone ◽  
Significant Difference

This study was undertaken to compare new bone formation between non-expired and expired bovine-derived xenogeneic bone substitute (expired, out-of-use period) and to evaluate the efficacy of argon (Ar)-based atmospheric pressure plasma (APP) treatment on expired bone substitute in rat calvarial defect. The groups were divided into (1) Non/Expired group (Using regular xenografts), (2) Expired group (Using expired xenografts), and (3) Ar/Expired group (Using Ar-based APP treated expired xenografts). Surface observation and cell experiments were performed in vitro. Twelve rats were used for in vivo experiment and the bony defects were created on the middle of the cranium. The bone substitute of each group was implanted into the defective site. After 4 weeks, all the rats were sacrificed, and the volumetric, histologic, and histometric analyses were performed. In the results of osteogenic differentiation and mineralization, Non/Expired and Ar/Expired groups were significantly higher than Expired group (p < 0.05). However, there was no significant difference between groups in the animal study (p > 0.05). Within the limitations of this study, the surface treatment of Ar-based APP has a potential effect on the surface modification of bone grafts. However, there was no significant difference in bone regeneration ability between groups in vivo; thus, studies on APP to enhance bone regeneration should be carried out in the future.

scholarly journals Preparation and Evaluation of Bioactivity of Porous Bioglass Tablets for Bone Tissue Regeneration

2019 ◽  
Vol 1 (3) ◽  
pp. 112-123
Author(s):  
Rohith Kumar R. ◽  
Sangeetha Ashok Kumar ◽  
K. Periyasami Bhuvana
Keyword(s):  
Surface Characterization ◽  
Mechanical Stability ◽  
Average Pore Size ◽  
High Surface ◽  
Bone Tissue Regeneration ◽  
Average Pore ◽  
Hydroxy Apatite ◽  
Sbf Solution

The present study endeavors in the preparation and characterization of semi crystalline 45S5 bioglass (BG) (SiO2-CaO-P2O5) through sol gel process. Dry press mold technique was used in the preparation porous BG tablets to examine the bioactivity through invitro studies. The synthesized BG powder was subjected to structural, morphological and mechanical characterization and the bioactivity was examined in vitro by immersing the BG tablet in the Simulated Body Fluid (SBF) solution. XRD pattern and the SEM micrographs revealed the semi crystalline nature of BG with spherical morphology. The elemental analysis confirms the presence of vital constituents required for Bone regeneration (Calcium, Phosphorous, Silica, and Sodium). The surface characterization of BG tablet reveals the pores structure of average pore size of 240nm which contributed to the high surface activity resulting in formation of carbonated hydroxy apatite (HCAP) when immersed in SBF. The disintegration studies denoted the stabilization period was after 48 of immersion of BG tablets in SBF solution. The compressive strength measurement of the tablet also reveals the higher mechanical stability.

scholarly journals Influence of Hydroxyapatite Surface Functionalization on Thermal and Biological Properties of Poly(l-Lactide)- and Poly(l-Lactide-co-Glycolide)-Based Composites

2020 ◽  
Vol 21 (18) ◽  
pp. 6711
Author(s):  
Małgorzata Gazińska ◽  
Anna Krokos ◽  
Magdalena Kobielarz ◽  
Marcin Włodarczyk ◽  
Paulina Skibińska ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Surface Functionalization ◽  
Biological Properties ◽  
Polymorphic Form ◽  
Cold Crystallization ◽  
Composition Analysis ◽  
Melt Crystallization ◽  
Crystallinity Degree ◽  
Surface Modified

Novel biocomposites of poly(L-lactide) (PLLA) and poly(l-lactide-co-glycolide) (PLLGA) with 10 wt.% of surface-modified hydroxyapatite particles, designed for applications in bone tissue engineering, are presented in this paper. The surface of hydroxyapatite (HAP) was modified with polyethylene glycol by using l-lysine as a linker molecule. The modification strategy fulfilled two important goals: improvement of the adhesion between the HAP surface and PLLA and PLLGA matrices, and enhancement of the osteological bioactivity of the composites. The surface modifications of HAP were confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), TGA, and elemental composition analysis. The influence of hydroxyapatite surface functionalization on the thermal and in vitro biological properties of PLLA- and PLLGA-based composites was investigated. Due to HAP modification with polyethylene glycol, the glass transition temperature of PLLA was reduced by about 24.5 °C, and melt and cold crystallization abilities were significantly improved. These achievements were scored based on respective shifting of onset of melt and cold crystallization temperatures and 1.6 times higher melt crystallization enthalpy compared with neat PLLA. The results showed that the surface-modified HAP particles were multifunctional and can act as nucleating agents, plasticizers, and bioactive moieties. Moreover, due to the presented surface modification of HAP, the crystallinity degree of PLLA and PLLGA and the polymorphic form of PLLA, the most important factors affecting mechanical properties and degradation behaviors, can be controlled.

scholarly journals Surface-Modified Multifunctional Thymol-Loaded Biodegradable Nanoparticles for Topical Acne Treatment

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1501
Author(s):  
Camila Folle ◽  
Natalia Díaz-Garrido ◽  
Elena Sánchez-López ◽  
Ana Maria Marqués ◽  
Josefa Badia ◽  
...  
Keyword(s):  
Wound Healing ◽  
Surface Functionalization ◽  
Ex Vivo ◽  
Skin Penetration ◽  
Topical Administration ◽  
Antibacterial Performance ◽  
Cutibacterium Acnes ◽  
Anti Inflammatory ◽  
Surface Modified

The present work is focused on the development of novel surface-functionalized poly(lactic-co-glycolic acid) nanoparticles loaded with thymol (TH-NPs) for topical administration enhancing thymol anti-inflammatory, antioxidant and wound healing activities against acne. TH-NPs were prepared by solvent evaporation method using different surface functionalization strategies and obtaining suitable physicochemical parameters and a good short-term stability at 4 °C. Moreover, TH-NPs skin penetration and antioxidant activity were assessed in ex vivo pig skin models. Skin penetration of TH-NPs followed the follicular route, independently of the surface charge and they were able to enhance antioxidant capacity. Furthermore, antimicrobial activity against Cutibacterium acnes was evaluated in vitro by the suspension test showing improved antibacterial performance. Using human keratinocyte cells (HaCat), cytotoxicity, cellular uptake, antioxidant, anti-inflammatory and wound healing activities were studied. TH-NPs were non-toxic and efficiently internalized inside the cells. In addition, TH-NPs displayed significant anti-inflammatory, antioxidant and wound healing activities, which were highly influenced by TH-NPs surface modifications. Moreover, a synergic activity between TH-NPs and their surface functionalization was demonstrated. To conclude, surface-modified TH-NPs had proven to be suitable to be used as anti-inflammatory, antioxidant and wound healing agents, constituting a promising therapy for treating acne infection and associated inflammation.

The Sintering Behaviour and Mechanical Properties of Hydroxyapatite - Based Composites for Bone Tissue Regeneration

2018 ◽  
Vol 69 (5) ◽  
pp. 1272-1275 ◽  
Author(s):  
Camelia Tecu ◽  
Aurora Antoniac ◽  
Gultekin Goller ◽  
Mustafa Guven Gok ◽  
Marius Manole ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tricalcium Phosphate ◽  
Cosmetic Surgery ◽  
Mechanical Stability ◽  
Raw Materials ◽  
Oyster Shell ◽  
Bone Tissue Regeneration ◽  
Sintering Behavior ◽  
Bovine Bone ◽  
Human Teeth

Bone reconstruction is a complex process which involves an osteoconductive matrix, osteoinductive signaling, osteogenic cells, vascularization and mechanical stability. Lately, to improve the healing of the bone defects and to accelerate the bone fusion and bone augmentation, bioceramic composite materials have been used as bone substitutes in the field of orthopedics and dentistry, as well as in cosmetic surgery. Of all types of bioceramics, the most used is hydroxyapatite, because of its similar properties to those of the human bone and better mechanical properties compared to b-tricalcium phosphate [1]. Currently, the most used raw materials sources for obtaining the hydroxyapatite are: bovine bone, seashells, corals, oyster shell, eggshells and human teeth. There are two common ways to obtain hydroxyapatite: synthetically and naturally. Generally, for the improvement of the mechanical properties and the structural one, hydroxyapatite is subjected to the sintering process. Considering the disadvantages of hydroxyapatite such as poor biodegradation rate, b-TCP has been developed, which has some disadvantages too, such as brittleness. For this reason, the aim of this study is to look into the effect of adding magnesium oxide on the sintering behavior, the structure and the mechanical properties of the hydroxyapatite-tricalcium phosphate composites.

scholarly journals Dual Network Composites of Poly(vinyl alcohol)-Calcium Metaphosphate/Alginate with Osteogenic Ions for Bone Tissue Engineering in Oral and Maxillofacial Surgery

2021 ◽  
Vol 8 (8) ◽  
pp. 107
Author(s):  
Lilis Iskandar ◽  
Lucy DiSilvio ◽  
Jonathan Acheson ◽  
Sanjukta Deb
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Vinyl Alcohol ◽  
Maxillofacial Surgery ◽  
Bone Defects ◽  
Bone Tissue Regeneration ◽  
Poly Vinyl Alcohol ◽  
Oral And Maxillofacial Surgery

Despite considerable advances in biomaterials-based bone tissue engineering technologies, autografts remain the gold standard for rehabilitating critical-sized bone defects in the oral and maxillofacial (OMF) region. A majority of advanced synthetic bone substitutes (SBS’s) have not transcended the pre-clinical stage due to inferior clinical performance and translational barriers, which include low scalability, high cost, regulatory restrictions, limited advanced facilities and human resources. The aim of this study is to develop clinically viable alternatives to address the challenges of bone tissue regeneration in the OMF region by developing ‘dual network composites’ (DNC’s) of calcium metaphosphate (CMP)—poly(vinyl alcohol) (PVA)/alginate with osteogenic ions: calcium, zinc and strontium. To fabricate DNC’s, single network composites of PVA/CMP with 10% (w/v) gelatine particles as porogen were developed using two freeze–thawing cycles and subsequently interpenetrated by guluronate-dominant sodium alginate and chelated with calcium, zinc or strontium ions. Physicochemical, compressive, water uptake, thermal, morphological and in vitro biological properties of DNC’s were characterised. The results demonstrated elastic 3D porous scaffolds resembling a ‘spongy bone’ with fluid absorbing capacity, easily sculptable to fit anatomically complex bone defects, biocompatible and osteoconductive in vitro, thus yielding potentially clinically viable for SBS alternatives in OMF surgery.

scholarly journals Plectin ensures intestinal epithelial integrity and protects colon against colitis

2021 ◽  
Vol 14 (3) ◽  
pp. 691-702
Author(s):  
Alzbeta Krausova ◽  
Petra Buresova ◽  
Lenka Sarnova ◽  
Gizem Oyman-Eyrilmez ◽  
Jozef Skarda ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Intestinal Barrier ◽  
Intercellular Junctions ◽  
Protein Profiling ◽  
Cell Junctions ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Critical Determinant ◽  
In Vitro Feeding

AbstractPlectin, a highly versatile cytolinker protein, provides tissues with mechanical stability through the integration of intermediate filaments (IFs) with cell junctions. Here, we hypothesize that plectin-controlled cytoarchitecture is a critical determinant of the intestinal barrier function and homeostasis. Mice lacking plectin in an intestinal epithelial cell (IEC; PleΔIEC) spontaneously developed colitis characterized by extensive detachment of IECs from the basement membrane (BM), increased intestinal permeability, and inflammatory lesions. Moreover, plectin expression was reduced in the colons of ulcerative colitis (UC) patients and negatively correlated with the severity of colitis. Mechanistically, plectin deficiency in IECs led to aberrant keratin filament (KF) network organization and the formation of dysfunctional hemidesmosomes (HDs) and intercellular junctions. In addition, the hemidesmosomal α6β4 integrin (Itg) receptor showed attenuated association with KFs, and protein profiling revealed prominent downregulation of junctional constituents. Consistent with the effects of plectin loss in the intestinal epithelium, plectin-deficient IECs exhibited remarkably reduced mechanical stability and limited adhesion capacity in vitro. Feeding mice with a low-residue liquid diet that reduced mechanical stress and antibiotic treatment successfully mitigated epithelial damage in the PleΔIEC colon.

In vitro effects of temperature on red blood cell deformability and membrane stability in human and various vertebrate species

2021 ◽  
pp. 1-10
Author(s):  
Adam Attila Matrai ◽  
Gabor Varga ◽  
Bence Tanczos ◽  
Barbara Barath ◽  
Adam Varga ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Mechanical Stability ◽  
Cell Deformability ◽  
Blood Samples ◽  
Effects Of Temperature ◽  
The Way ◽  
Rbc Deformability

BACKGROUND: The effects of temperature on micro-rheological variables have not been completely revealed yet. OBJECTIVE: To investigate micro-rheological effects of heat treatment in human, rat, dog, and porcine blood samples. METHODS: Red blood cell (RBC) - buffer suspensions were prepared and immersed in a 37, 40, and 43°C heat-controlled water bath for 10 minutes. Deformability, as well as mechanical stability of RBCs were measured in ektacytometer. These tests were also examined in whole blood samples at various temperatures, gradually between 37 and 45°C in the ektacytometer. RESULTS: RBC deformability significantly worsened in the samples treated at 40 and 43°C degrees, more expressed in human, porcine, rat, and in smaller degree in canine samples. The way of heating (incubation vs. ektacytometer temperation) and the composition of the sample (RBC-PBS suspension or whole blood) resulted in the different magnitude of RBC deformability deterioration. Heating affected RBC membrane (mechanical) stability, showing controversial alterations. CONCLUSION: Significant changes occur in RBC deformability by increasing temperature, showing inter-species differences. The magnitude of alterations is depending on the way of heating and the composition of the sample. The results may contribute to better understanding the micro-rheological deterioration in hyperthermia or fever.

The Effectiveness of a Hinged Elbow Orthosis in Medial Collateral Ligament Injuries: An In Vitro Biomechanical Study

2019 ◽  
Vol 47 (12) ◽  
pp. 2827-2835
Author(s):  
Ranita H.K. Manocha ◽  
James A. Johnson ◽  
Graham J.W. King
Keyword(s):  
Medial Collateral Ligament ◽  
Muscle Activation ◽  
Mechanical Stability ◽  
Biomechanical Study ◽  
Return To Play ◽  
Collateral Ligament ◽  
Valgus Stress ◽  
Active Motion ◽  
Early Return

Background: Medial collateral ligament (MCL) injuries are common after elbow trauma and in overhead throwing athletes. A hinged elbow orthosis (HEO) is often used to protect the elbow from valgus stress early after injury and during early return to play. However, there is minimal evidence regarding the efficacy of these orthoses in controlling instability and their influence on long-term clinical outcomes. Purpose: (1) To quantify the effect of an HEO on elbow stability after simulated MCL injury. (2) To determine whether arm position, forearm rotation, and muscle activation influence the effectiveness of an HEO. Study Design: Controlled laboratory study. Methods: Seven cadaveric upper extremity specimens were tested in a custom simulator that enabled elbow motion via computer-controlled actuators and motors attached to relevant tendons. Specimens were examined in 2 arm positions (dependent, valgus) and 2 forearm positions (pronation, supination) during passive and simulated active elbow flexion while unbraced and then while braced with an HEO. Testing was performed in intact elbows and repeated after simulated MCL injury. An electromagnetic tracking device measured valgus angulation as an indicator of elbow stability. Results: When the arm was dependent, the HEO increased valgus angle with the forearm in pronation (+1.0°± 0.2°, P = .003) and supination (+1.5°± 0.0°, P = .006) during active motion. It had no significant effect on elbow stability during passive motion. In the valgus position, the HEO had no effect on elbow stability during passive or active motion in pronation and supination. With the arm in the valgus position with the HEO, muscle activation reduced instability during pronation (–10.3°± 2.5°, P = .006) but not supination ( P = .61). Conclusion: In this in vitro study, this HEO did not enhance mechanical stability when the arm was in the valgus and dependent positions after MCL injury. Clinical Relevance: After MCL injury, an HEO likely does not provide mechanical elbow stability during rehabilitative exercises or when the elbow is subjected to valgus stress such as occurs during throwing.

In Vitro Mineralization and Cell Adhesion on Surface Modified Poly (2 - hydroxy ethyl methacrylate-co-methyl methacrylate

2006 ◽  
Vol 309-311 ◽  
pp. 493-496 ◽  
Author(s):  
G.S. Sailaja ◽  
T.V. Kumari ◽  
Yoshiyuki Yokogawa ◽  
H.K. Varma
Keyword(s):  
Cell Adhesion ◽  
Calcium Phosphate ◽  
Methyl Methacrylate ◽  
Radical Copolymerization ◽  
Sem Analysis ◽  
Free Radical Copolymerization ◽  
In Vitro Mineralization ◽  
Atr Spectroscopy ◽  
Surface Modified

Poly(2-hydroxyethyl methacrylate-co- methyl methacrylate) HM, was synthesized by free radical copolymerization, cross-linked with ethylene glycol dimethacrylate and phosphorylated. The phosphate coupling was ensured by ATR spectroscopy. The in vitro mineralization ability of the phosphorylated HM (designated as PHM) was investigated by studying the nucleation and growth of calcium phosphate on its surface by immersing in simulated body fluid (SBF) solution. The coating morphology was studied by SEM and the Ca/P ratio of the coating by EDX analysis. The cell adhesion behaviour of PHM was studied by seeding Human osteosarcoma (HOS) cells for one week followed by SEM analysis along with HM as control. It was observed that HOS cells exhibited biomineralization of calcium phosphate on the surface of HM as well as on PHM with a significantly higher amount on the surface of PHM as observed by von kossa staining method. The results show that PHM is capable of in vitro mineralization under simulated physiological condition, promotes cell adhesion by providing an excellent cell friendly surface and it exhibits biomineralization of calcium phosphate in presence of HOS cells.

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