scholarly journals Novel Chitosan-Silica Hybrid Hydrogels for Cell Encapsulation and Drug Delivery

2021 ◽  
Vol 22 (22) ◽  
pp. 12267
Author(s):  
Soher N. Jayash ◽  
Paul R. Cooper ◽  
Richard M. Shelton ◽  
Sarah A. Kuehne ◽  
Gowsihan Poologasundarampillai

Hydrogels constructed from naturally derived polymers provide an aqueous environment that encourages cell growth, however, mechanical properties are poor and degradation can be difficult to predict. Whilst, synthetic hydrogels exhibit some improved mechanical properties, these materials lack biochemical cues for cells growing and have limited biodegradation. To produce hydrogels that support 3D cell cultures to form tissue mimics, materials must exhibit appropriate biological and mechanical properties. In this study, novel organic-inorganic hybrid hydrogels based on chitosan and silica were prepared using the sol-gel technique. The chemical, physical and biological properties of the hydrogels were assessed. Statistical analysis was performed using One-Way ANOVAs and independent-sample t-tests. Fourier transform infrared spectroscopy showed characteristic absorption bands including amide II, Si-O and Si-O-Si confirming formation of hybrid networks. Oscillatory rheometry was used to characterise the sol to gel transition and viscoelastic behaviour of hydrogels. Furthermore, in vitro degradation revealed both chitosan and silica were released over 21 days. The hydrogels exhibited high loading efficiency as total protein loading was released in a week. There were significant differences between TC2G and C2G at all-time points (p < 0.05). The viability of osteoblasts seeded on, and encapsulated within, the hydrogels was >70% over 168 h culture and antimicrobial activity was demonstrated against Pseudomonas aeruginosa and Enterococcus faecalis. The hydrogels developed here offer alternatives for biopolymer hydrogels for biomedical use, including for application in drug/cell delivery and for bone tissue engineering.

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 261-266 ◽  
Author(s):  
L. P. Silva ◽  
M. D. P. Ribeiro ◽  
E. S. Trichês ◽  
M. Motisuke

Abstract Calcium phosphate cements (CPCs) are potential materials for repairing bone defects, mainly due to their excellent biocompatibility and osteoconductivity. Nevertheless, their low mechanical properties limit their usage in clinical applications. The gelatin addition may improve the mechanical and biological properties of CPCs, but their solubility in water may increase the porosity of the cement during degradation. Thus, the aim of this work was to investigate the influence of gelatin on the setting time, compressive strength and degradation rate of a brushite cement. CPCs were prepared with the addition of 0, 5, 10 and 20 wt% of gelatin powder in the solid phase of the cement. The results indicated that the setting time increased with gelatin. Furthermore, cement with 20 wt% of gelatin had an initial compressive strength of 14.1±1.8 MPa while cement without gelatin had 4.5±1.2 MPa. The weight loss, morphology and compressive strength were evaluated after degradation in Ringer’s solution. According to the weight loss data, gelatin was eliminated of samples during degradation. It was concluded that the presence of gelatin improved CPCs mechanical properties; however, as degradation in Ringer’s solution evolved, cement compressive strength decreased due to gelatin dissolution and, consequently, an increase in sample porosity.


2007 ◽  
Vol 361-363 ◽  
pp. 139-142 ◽  
Author(s):  
Xin Chang Shi ◽  
H.Z. Jiang ◽  
J. Xue ◽  
Yun Mao Liao ◽  
L.Y. Xiao ◽  
...  

In order to modify the biological properties of pure hydroxyapatite (HAp), two kinds of zinc-containing HAp, which had zinc content of 5.10wt% and 2.54wt%, respectively, were synthesized via sol-gel technique. The obtained coatings were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Then the antibacterial effects were evaluated through bacteriostatic test on Streptococcus mutans (S.mutans) in vitro and zinc ions releasing ability was investigated through detecting the zinc ions concentration by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The obtained coatings were observed to possess typical apatite peaks in XRD patterns and high homogeneous and porous surfaces in SEM morphology. The coating layer demonstrated good releasing ability in Brain Heart Infusion (BHI) liquid and obviously inhibitory effects to the growth and proliferation of S. mutans. Based on the results obtained above, it is concluded that the sol-gel derived zinc-containing hydroxyapatite could be applied as an antibacterial effective biomaterial.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1930 ◽  
Author(s):  
Ming-You Shie ◽  
Jian-Jr Lee ◽  
Chia-Che Ho ◽  
Ssu-Yin Yen ◽  
Hooi Yee Ng ◽  
...  

Gelatin-methacryloyl (GelMa) is a very versatile biomaterial widely used in various biomedical applications. The addition of methacryloyl makes it possible to have hydrogels with varying mechanical properties due to its photocuring characteristics. In addition, gelatin is obtained and derived from natural material; thus, it retains various cell-friendly motifs, such as arginine-glycine-aspartic acid, which then provides implanted cells with a friendly environment for proliferation and differentiation. In this study, we fabricated human dermal fibroblast cell (hDF)-laden photocurable GelMa hydrogels with varying physical properties (5%, 10%, and 15%) and assessed them for cellular responses and behavior, including cell spreading, proliferation, and the degree of extracellular matrix remodeling. Under similar photocuring conditions, lower concentrations of GelMa hydrogels had lower mechanical properties than higher concentrations. Furthermore, other properties, such as swelling and degradation, were compared in this study. In addition, our findings revealed that there were increased remodeling and proliferation markers in the 5% GelMa group, which had lower mechanical properties. However, it was important to note that cellular viabilities were not affected by the stiffness of the hydrogels. With this result in mind, we attempted to fabricate 5–15% GelMa scaffolds (20 × 20 × 3 mm3) to assess their feasibility for use in skin regeneration applications. The results showed that both 10% and 15% GelMa scaffolds could be fabricated easily at room temperature by adjusting several parameters, such as printing speed and extrusion pressure. However, since the sol-gel temperature of 5% GelMa was noted to be lower than its counterparts, 5% GelMa scaffolds had to be printed at low temperatures. In conclusion, GelMa once again was shown to be an ideal biomaterial for various tissue engineering applications due to its versatile mechanical and biological properties. This study showed the feasibility of GelMa in skin tissue engineering and its potential as an alternative for skin transplants.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 61 ◽  
Author(s):  
Yannan Liu ◽  
Juan Gu ◽  
Daidi Fan

A novel, three-dimensional, porous, human-like collagen (HLC)/nano-hydroxyapatite (n-HA) scaffold cross-linked by 1,2,7,8-diepoxyoctane (DEO) was successfully fabricated, which showed excellent mechanical and superior biological properties for bone tissue regeneration in this study. The physicochemical characterizations of different n-HA/HLC/DEO (nHD) scaffolds were investigated by determining the morphology, compression stress, elastic modulus, Young’s modulus and enzymatic hydrolysis behavior in vitro. The results demonstrated that nHD-2 and nHD-3 scaffolds showed superior mechanical properties and resistance to enzymatic hydrolysis compared to nHD-1 scaffolds. The cell viability, live cell staining and cell adhesion analysis results demonstrated that nHD-2 scaffolds exhibited low cytotoxicity and excellent cytocompatibility compared with nHD-1 and nHD-3 scaffolds. Furthermore, subcutaneous injections of nHD-2 scaffolds in rabbits produced superior anti-biodegradation effects and histocompatibility compared with injections of nHD-1 and nHD-3 scaffolds after 1, 2 and 4 weeks. In addition, the repair of bone defects in rabbits demonstrated that nHD-2 scaffolds presented an improved ability for guided bone regeneration and reconstruction compared to commercially available bone scaffold composite hydroxyapatite/collagen (HC). Collectively, the results show that nHD-2 scaffolds show promise for application in bone tissue engineering due to their excellent mechanical properties, anti-biodegradation, anti-biodegradation, biocompatibility and bone repair effects.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2711
Author(s):  
Ana S. Neto ◽  
Daniela Brazete ◽  
José M.F. Ferreira

The combination of calcium phosphates with bioactive glasses (BG) has received an increased interest in the field of bone tissue engineering. In the present work, biphasic calcium phosphates (BCP) obtained by hydrothermal transformation of cuttlefish bone (CB) were coated with a Sr-, Mg- and Zn-doped sol-gel derived BG. The scaffolds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. The initial CB structure was maintained after hydrothermal transformation (HT) and the scaffold functionalization did not jeopardize the internal structure. The results of the in-vitro bioactivity after immersing the BG coated scaffolds in simulated body fluid (SBF) for 15 days showed the formation of apatite on the surface of the scaffolds. Overall, the functionalized CB derived BCP scaffolds revealed promising properties, but further assessment of the in-vitro biological properties is needed before being considered for their use in bone tissue engineering applications.


2013 ◽  
Vol 11 (9) ◽  
pp. 1403-1411 ◽  
Author(s):  
Zuzana Balgová ◽  
Martin Palou ◽  
Jaromír Wasserbauer ◽  
Jana Kozánková

AbstractAbstract A series of poly(vinyl alcohol) membranes reinforced with hydroxyapatite in various weight percent — 0%, 10%, 20%, 30%, 40% and 50% were prepared. Hydroxyapatite was prepared by a sol-gel procedure using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as starting materials in an alkaline aqueous environment and then mixed with a solution of poly(vinyl alcohol), which was prepared by dissolving it in water at 85°C. The different mixtures were cast in a mould and evaporated for 7 days at a temperature of 30°C to obtain 1 mm thin membranes. FTIR spectroscopy was used to identify the different functional groups in the composites. The surface morphology was examined using a scanning electron microscope. In vitro bioactivity tests in Simulated Blood Fluid were performed for up to 28 days, especially for the membrane containing 50 wt.% HA. SEM was used to characterise the surface microstructure of biocomposite membranes before and after soaking in SBF. It was observed that the formation of clusters in membranes increases with increasing amount of HA. The clusters are formed due to agglomeration and crystal growth of HA particles during drying of the membranes. The in vitro bioactivity was found to increase with soaking time of biocomposite materials in simulated blood fluid. Graphical abstract


2014 ◽  
Vol 631 ◽  
pp. 30-35 ◽  
Author(s):  
S. Solgi ◽  
M. Shahrezaee ◽  
A. Zamanian ◽  
T.S. Jafarzadeh Kashi ◽  
Majid Raz ◽  
...  

Bioactive glass of the type CaO–SrO–P2O5–SiO2was obtained by the sol-gel processing method. Three samples containing 0 mol%, 5 mol% and 10 mol% of SrO were synthesized. The obtained bioactive glasses were characterized by the techniques such as, X-ray diffraction (XRD) and scanning electron microscope (SEM) and the effect of SrO/CaO substitution on in vitro biological properties of the synthesized glasses were evaluated and biocompatibility of the samples was measured using MTT assay. The results showed that incorporation of Sr in the obtained glass network did not result in any structural alteration of it due to the similar role of SrO compared with that of CaO. In vitro experiments with human osteosarcoma cell lines (MG-63) and MTT assay indicated that bioactive glass incorporating 5 mol% of Sr in the composition is non-toxic and revealed good biocompatibility.


2018 ◽  
Vol 12 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Sina Khoshsima ◽  
Ammar Alshemary ◽  
Aysen Tezcaner ◽  
Sedat Surdem ◽  
Zafer Evis

In this study, hydroxyapatite-B2O3-La2O3 composites (with ? 20 wt.%B2O3 and ? 2 wt.% La2O3) were synthesized via wet precipitation method and calcined at 1100?C for 1 h. X-ray diffraction (XRD) analysis revealed the existence of the pure hydroxyapatite (HA) phase with high crystallinity. Characteristic absorption bands of HA were also observed in Fourier transform infrared spectra. Furthermore, scanning electron microscopy images demonstrated that the addition of B2O3 and La2O3 into HA enhanced the particle growth. Mechanical properties of the composites were studied by diametral tensile test and the results showed that incorporation of 10 wt.% B2O3 and 2 wt.% La2O3 led to a 39% increase in tensile strength (compared to the pure HA). In vitro cytocompatibility of HA-B2O3-La2O3 composites was investigated using Osteosarcoma Cell Lines (Saos-2). Incorporation of B2O3 and La2O3 into HA had no toxic effect towards the cells. Based on its tensile strength properties and biological response, composite of 88 wt.% HA, 10 wt.% B2O3 and 2 wt.% La2O3 was suggested as a promising composite for bone tissue engineering applications.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2674
Author(s):  
Giulia Morello ◽  
Alessandro Polini ◽  
Francesca Scalera ◽  
Riccardo Rizzo ◽  
Giuseppe Gigli ◽  
...  

In recent years, growing attention has been directed to the development of 3D in vitro tissue models for the study of the physiopathological mechanisms behind organ functioning and diseases. Hydrogels, acting as 3D supporting architectures, allow cells to organize spatially more closely to what they physiologically experience in vivo. In this scenario, natural polymer hybrid hydrogels display marked biocompatibility and versatility, representing valid biomaterials for 3D in vitro studies. Here, thermosensitive injectable hydrogels constituted by chitosan and pectin were designed. We exploited the feature of chitosan to thermally undergo sol–gel transition upon the addition of salts, forming a compound that incorporates pectin into a semi-interpenetrating polymer network (semi-IPN). Three salt solutions were tested, namely, beta-glycerophosphate (βGP), phosphate buffer (PB) and sodium hydrogen carbonate (SHC). The hydrogel formulations (i) were injectable at room temperature, (ii) gelled at 37 °C and (iii) presented a physiological pH, suitable for cell encapsulation. Hydrogels were stable in culture conditions, were able to retain a high water amount and displayed an open and highly interconnected porosity and suitable mechanical properties, with Young’s modulus values in the range of soft biological tissues. The developed chitosan/pectin system can be successfully used as a 3D in vitro platform for studying tissue physiopathology.


2019 ◽  
Vol 34 (2) ◽  
pp. 131-149 ◽  
Author(s):  
KR Remya ◽  
Sunitha Chandran ◽  
Annie John ◽  
P Ramesh

This study explores the potential of electrospun polycaprolactone scaffolds for the controlled delivery of pamidronate disodium pentahydrate, an amino-bisphosphonate drug used for the treatment of osteoporosis. Major drawbacks associated with oral bisphosphonate therapy are its poor bioavailability and gastrointestinal side-effects. Herein, we used polycaprolactone, a well-known Food and Drug Administration–approved biomaterial, as the delivering vehicle for pamidronate disodium pentahydrate. Scaffolds based on polycaprolactone with three different formulations (1, 3, and 5 wt%) of pamidronate disodium pentahydrate were fabricated by electrospinning, and a comparative study was carried out to evaluate the effect of pamidronate disodium pentahydrate on physico-mechanical and biological properties of polycaprolactone. The observations from Fourier-transform infrared spectra and thermogravimetric analysis confirmed the successful incorporation of pamidronate disodium pentahydrate into polycaprolactone scaffolds. The study also revealed that pamidronate disodium pentahydrate–loaded scaffolds exhibited improved hydrophilicity as well as superior mechanical properties as depicted by the contact angle measurements and mechanical property evaluation. In vitro drug release studies of pamidronate disodium pentahydrate–loaded scaffolds in phosphate buffer saline at 37°C showed that all the scaffolds exhibited controlled release of pamidronate disodium pentahydrate. In vitro degradation studies further revealed that pamidronate disodium pentahydrate incorporated polycaprolactone scaffolds degraded faster as depicted by the fiber rupture and drop in mechanical properties. In vitro cell culture studies using human osteosarcoma cell lines demonstrated that pamidronate disodium pentahydrate–loaded polycaprolactone scaffolds were cytocompatible. The human osteosarcoma cells had favorable interaction with the scaffolds, and the viability of adhered cells was depicted by the fluorescein diacetate/propidium iodide staining. MTT assay further revealed enhanced cell viability on PCL/PDS3 scaffolds. Our findings bespeak that the pamidronate disodium pentahydrate–encapsulated electrospun polycaprolactone scaffolds have the potential to serve as a promising drug delivery vehicle for osteoporotic bone defect repair.


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