Biological Tissue Engineering Research Articles

Chondral and Osteochondritis Dissecans Lesions Treated by Autologous Chondrocytes Implantation: A Mid- to Long-Term Nonrandomized Comparison.

The aim of this study was to compare the clinical outcome of cartilage repair with autologous chondrocyte implantation (ACI) in patients with osteochondritis dissecans (OCD) lesions and full-thickness cartilage lesions. This study included a cohort of 115 consecutive patients with a cartilage lesion of the knee treated with ACI. Of the patients, 35 had an OCD lesion and 80 a full-thickness cartilage lesion. During a follow-up period from 2 to 13 years all treatment failures were identified. The failure rate between OCD lesions and full-thickness cartilage lesions was compared with Kaplan-Meier analysis. Patient-reported outcome was evaluated 2 years postoperatively with the Lysholm score. During the follow-up 21 out of 115 patients encountered a treatment failure. The failure rate for full-thickness cartilage lesions was 19.1% and for OCD lesions 43.3% over the 10-year follow-up. Patient-reported outcome improved from baseline to 2 years postoperatively. The improvement from baseline was statistically significant, and the Lysholm score improved more than the minimal clinically important difference. The patient-reported outcome showed no difference between lesion types at 2 years. In the presented retrospective study, the failure rate of first-generation ACI was higher in OCD lesions than in large full-thickness cartilage lesions, suggesting that OCD lesions may associate with properties that affect the durability of repair tissue. Future prospective studies are needed to tell us how to best repair OCD lesions with biological tissue engineering.

Biological bone tissue engineering with adipose stem cell combined gene therapy: A future prospect in treating oral peri-implant defects

IJASHNB - IP Indian J Anat Surg Head Neck Brain- Print ISSN No:-2581-5210 Online ISSN No:-2581-5229,IP Indian Journal of Anatomy and Surgery of Head, Neck and Brain (IJASHNB) open access, peer-reviewed quarterly journal publishing since 2015 and is published under the Khyati Education and Research Foundation (KER

The application and prospects of three dimensional bioprinting in urinary system reconstruction

Three dimensional (3D) bioprinting is a new biological tissue engineering technology in recent years. The development of 3D bioprinting is conducive to solving the current problems of clinical tissue and organ repairing. This article provides a review about the clinical and research status of 3D bioprinting and urinary system reconstruction. Furthermore, the feasibility and clinical value of 3D bioprinting in urinary system reconstruction will be also discussed.

Programmable Syringe Pump for Selective Micro Droplet Deposition

Micro/nanopatterns with micro deposition techniques have been used in various applications such as flexible electronic devices, biosensing, and biological tissue engineering. For depositing a small size of droplets that can be controlled, structured and patterned precisely is a very important process for microfabrication. In this study, we developed a low cost and simple system for fabricating micro/nanostructure by a selective micro deposition process using a syringe pump. This method is an additive fabrication method where selective droplet materials are released through a needle of the syringe pump. By translating the rotating stepper motor into a linear movement of the lead screw, it will press the plunger of the syringe and give a force to the fluid inside the syringe, hence a droplet can be injected out. The syringe pump system consists of a syringe, the mechanical unit, and the controller unit. A stepper motor, the lead screw, and the mechanical components are used for the mechanical unit. Arduino Uno microcontroller is used as the controller unit and can be programmed by the computer through GUI (Graphical User Interface). The input parameters, such as the push or pull of flow direction, flow rate, the droplet volume, and syringe size dimension can be inputted by the user as their desired value via keypad or the computer. The measurement results show that the syringe pump has characteristics: the maximum average error value of the measured volume is 2.5% and the maximum average error value of the measured flow rate is 14%. The benefits of a syringe pump for micro deposition can overcome photolithography weaknesses, which require an etching and stencil process in the manufacture of semiconductors. Combining two or more syringes into one system with different droplet materials can be used as a promising method for 3D microfabrication in the future.

Mechanical-chemical coupling in Temporomandibular Joint disc

This paper reports an experimental investigation based on vibrational spectroscopy of biological materials by a new custom-made device allowing simultaneously applying tensile load with changes within a controlled chemical environment. The response of the molecular structures of Temporomandibular Joint (TMJ) discs under simulated daily mechanical stimulations was characterized by stress–strain analysis and Raman spectra. The results show that changes in the biochemical environment around tissue (associated to common disorders) led to significant modifications to its mechanical properties. The molecular response to stress was then fully characterized by a combination of molecular mapping followed by statistical analysis via Principal Component Analysis resulting in the identification of the phenylalanine-aromatic amino acids as a significant mechanical-chemical effector of TMJ discs. The coupled tensile machine and vibrational spectroscopy approach enabling in-situ molecular studies proves to be a powerful technique for biological material characterization and tissue engineering.

Nanomaterials for bone tissue regeneration: updates and future perspectives.

Joint replacement and bone reconstructive surgeries are on the rise globally. Current strategies for implants and bone regeneration are associated with poor integration and healing resulting in repeated surgeries. A multidisciplinary approach involving basic biological sciences, tissue engineering, regenerative medicine and clinical research is required to overcome this problem. Considering the nanostructured nature of bone, expertise and resources available through recent advancements in nanobiotechnology enable researchers to design and fabricate devices and drug delivery systems at the nanoscale to be more compatible with the bone tissue environment. The focus of this review is to present the recent progress made in the rationale and design of nanomaterials for tissue engineering and drug delivery relevant to bone regeneration.

A critical review on the applications of fluid-structure interaction in porous media

PurposeThis study aims to investigate a critical review on the applications of fluid-structure interaction (FSI) in porous media.Design/methodology/approachTransport phenomena in porous media are of continuing interest by many researchers in the literature because of its significant applications in engineering and biomedical sectors. Such applications include thermal management of high heat flux electronic devices, heat exchangers, thermal insulation in buildings, oil recovery, transport in biological tissues and tissue engineering. FSI is becoming an important tool in the design process to fully understand the interaction between fluids and structures.FindingsThis study is structured in three sections: the first part summarizes some important studies on the applications of porous medium and FSI in various engineering and biomedical applications. The second part focuses on the applications of FSI in porous media as related to hyperthermia. The third part of this review is allocated to the applications of FSI of convection flow and heat transfer in engineering systems filled with porous medium.Research limitations/implicationsTo the best knowledge of the present authors, FSI analysis of turbulent flow in porous medium never been studied, and therefore, more attention should be given to this area in any future studies. Moreover, more studies should also be conducted on mixed convective flow and heat transfer in systems using porous medium and FSI.Practical implicationsThe wall of the blood vessel is considered as a flexible multilayer porous medium, and therefore, rigid wall analysis is not accurate, and therefore, FSI should be implemented for accurate predictions of flow and hemodynamic stresses.Social implicationsThe use of porous media theory in biomedical applications received a great attention by many investigators in the literature (Khanafer and Vafai, 2006a; Al-Amiri et al., 2014; Lasiello et al., 2016a, Lasiello et al., 2016b; Lasiello et al., 2015; Chung and Vafai, 2013; Mahjoob and Vafai, 2009; Yang and Vafai, 2008; Yang and Vafai, 2006; Ai and Vafai, 2006). A comprehensive review was conducted by Khanafer and Vafai (2006b) summarizing various studies associated with magnetic field imaging and drug delivery. The authors illustrated that the tortuosity and porosity had a profound effect on the diffusion process within the brain. AlAmiri et al. (2014) conducted a numerical study to investigate the effect of turbulent pulsatile flow and heating technique on the thermal distribution within the arterial wall. The results of that investigation illustrated that local heat flux variation along the bottom layer of the tumor was greater for the low-velocity condition. Yang and Vafai (2006) presented a comprehensive four-layer model to study low-density lipoprotein transport in the arterial wall coupled with a lumen (Figure 1). All the four layers (endothelium, intima, internal elastic lamina and media) were modeled as a homogenous porous medium.Originality/valueFuture studies on the applications of FSI in porous media are recommended in this review.

High antibacterial performance of electrospinning silk fibroin/gelatin film modified with graphene oxide‐sliver nanoparticles

ABSTRACTIn this study, graphene oxide‐sliver nanoparticle (GO‐AgNP) composite was synthesized in situ with GO as the raw material. Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy, and scanning electron microscopy were used to characterize the composite, the spherical Ag particles with a diameter of about 36 nm were well deposited on the surface of GO nanosheets without serious agglomeration, and the antibacterial properties of the composites were also tested. Moreover, the silk fibroin (SF)/gelatin (GT) electrospun nanofiber film was prepared by electrospinning, and the structure of the SF nanofiber film was observed using a Fourier transform infrared spectrometer, X‐ray diffractometer, and scanning electron microscope. The TGA curves indicated that the total weight loss rate of SF nanofibers at 400°C was significantly higher than that of SF/GT composite nanofibers (74.72% for pure SF, 62.37% for SF/GT nanocomposites). Finally, the GO‐AgNP composite was combined with electrospinning SF film, which resulted in the decrease in surface roughness from 393.5 ± 123.7 nm to 109.9 ± 24.43 nm and the decrease in contact angle from 82.48° to 54.78°. Besides, the GO‐AgNP composites enhanced the antibacterial performance of SF film greatly, which was conducive to its application in biological tissue engineering. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47904.

Toward Label-Free Selective Cell Separation of Different Eukaryotic Cell Lines Using Thermoresponsive Homopolymer Layers.

Ultrathin thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) homopolymer layers are reported as a novel platform for label-free temperature-stimulated cell separation from a coculture of eukaryotic cell lines. Pancreatic tumor cells (PaTu 8988t) and fibroblasts (NIH 3T3) were shown to attach and proliferate on PDEGMA layers with a dry thickness of 5 ± 1 nm at 37 °C. After the cell medium cooled to below the lower critical solution temperature (LCST), PaTu 8988t cells showed a significantly decreased cell area. By contrast, there was no significant change in cell area for NIH 3T3 cells, while they still exhibited lamellipodia and filopodia. PaTu 8988t cells could be detached at 22 °C after flushing gently with the cell medium, while negligible cell detachment was observed for NIH 3T3 cells under identical conditions. This significant difference between PaTu 8988t and NIH 3T3 was due to the different cell adhesion on the culture-medium-derived protein covering the PDEGMA layer. Thus, cell separation from a coculture was achieved successfully by cooling the cell medium to 22 °C, resulting in the desorption of 95 ± 6% of PaTu 8988t cells, while the NIH 3T3 cells remained adherent. Our findings provide an effective, label-free, rapid, and simple approach, exploiting a thermoresponsive homopolymer layer to separate and enrich or isolate cells from mixed cell populations for basic biological research, medical diagnostics, tissue engineering, and cell therapy.

Graphene-Reinforced Biodegradable Resin Composites for Stereolithographic 3D Printing of Bone Structure Scaffolds

A biodegradable UV-cured resin has been fabricated via stereolithography apparatus (SLA). The formulation consists of a commercial polyurethane resin as an oligomer, trimethylolpropane trimethacrylate (TEGDMA) as a reactive diluent and phenylbis (2, 4, 6-trimethylbenzoyl)-phosphine oxide (Irgacure 819) as a photoinitiator. The tensile strength of the three-dimensional (3D) printed specimens is 68 MPa, 62% higher than that of the reference specimens (produced by direct casting). The flexural strength and modulus can reach 115 MPa and 5.8 GPa, respectively. A solvent-free method is applied to fabricate graphene-reinforced nanocomposite. Porous bone structures (a jawbone with a square architecture and a sternum with a round architecture) and gyroid scaffold of graphene-reinforced nanocomposite for bone tissue engineering have been 3D printed via SLA. The UV-crosslinkable graphene-reinforced biodegradable nanocomposite using SLA 3D printing technology can potentially remove important cost barriers for personalized biological tissue engineering as compared to the traditional mould-based multistep methods.

Cell culture distribution in a three-dimensional porous scaffold in perfusion bioreactor

MotivationIt has been widely demonstrated that perfusion bioreactors improve in vitro cell culture on three-dimensional (3D) matrices. GoalWe aimed to determine the local cell distribution, based on the pore diameter, within a 3D scaffold during cell growth in a perfusion bioreactor. Materials and methodsScaffolds under perfusion were collected at 0, 4, and 7 days of culture; scaffold morphology and cell distribution within the construct were evaluated by imaging analysis. A mathematical model representing the cell growth heterogeneity in 3D perfusion bioreactor was developed; a specific rate equation for glucose was experimentally determined. Model accuracy was assessed comparing the cell proliferation predictions with experimental data. ResultsCell proliferation was successfully determined by coupling cell imaging with an ad hoc algorithm. The total number of cells in the scaffold, the number of cells for a single cross section, and the local cell distribution based on the scaffold pore size, were determined. Good agreement between computations and experiments was observed. ConclusionsA new methodology was developed to determine the cell heterogeneity within a 3D scaffold under perfusion. The proposed approach provides a helpful tool for 3D dynamic cell culture optimization for biological studies and tissue engineering applications.

Recent progress of solidification of suspensions

Suspensions include solvent and uniformly dispersed particles. Solidification of suspensions is to freeze the solvent while numerous particles disturb the pattern formation during the growth of the solid/liquid interface. It is a new interdisciplinary subject, involving the fields of freeze-casting porous materials, frost heaving, sea ice and biological tissue engineering and so on. Especially in recent years, many advanced materials with excellent properties were developed based on the processing of suspension solidification. Experimental phenomenon in suspension solidification is different from that in alloy solidification, such as the close-packed particle layer and self assembly, the ice lamellae structure and the periodic ice lenses and so on. Up to now, the formation mechanisms of these microstructures are still unclear. In this paper, we first review the historical development of suspension solidification in theory and in experiment. Then we demonstrate some recent progress of microstructural evolution and dynamical particle packing of suspension solidification. Finally, the outlooks of the future study on solidification of suspensions are also presented.

Mechanical-Chemical Coupling in Temporomandibular Joint Disc

This paper reports an experimental investigation based on vibrational spectroscopy of biological materials by a new custom-made device allowing simultaneously applying tensile load with changes within a controlled chemical environment. The response of the molecular structures of Temporomandibular Joint (TMJ) discs under simulated daily mechanical stimulations was characterized by stress-strain analysis and Raman spectra. The results show that changes in the biochemical environment around tissue (associated to common disorders) led to significant modifications to its mechanical properties. The molecular response to stress was then fully characterized by a combination of molecular mapping followed by statistical analysis via Principal Component Analysis resulting in the identification of the phenylalanine-aromatic amino acids as a significant and major mechanical-chemical effector of TMJ discs. The coupled tensile machine and vibrational spectroscopy approach enabling in-situ molecular studies proves to be a powerful technique for biological material characterization and tissue engineering.

Cells integration onto scaffolds prepared from polyester based polymers – importance of polymer thermal properties in addition to hydrophilicity

Three-dimensional (3D) scaffolds represent valuable tools for biological studies and tissue engineering applications. They offer better biological environment that better mimic 3 D dynamic in vivo conditions compared with conventional bidimentional (2D) cell culture systems. The integration of cells within the scaffolds is, however, dependent on their properties. In the present study, porous scaffolds were prepared from poly lactide (PLA), poly lactide polyethylene glycol copolymer (PLA-PEG) and poly lactide-co-glycolide – polyethylene glycol copolymer (PLGA-PEG) using porogen leaching method with NaCl particles as porogen. The three scaffolds were prepared with identical conditions (concentration, dimensions, porogen weight fraction and particle size) in order to evaluate the impact of polymer composition and properties on scaffold characteristics (internal architecture and pores distribution), as well as fibroblasts integration and proliferation within the scaffold 3 D network. The impact of hydrophilicity, water uptake and protein adsorption are discussed. The data shows that amorphous polymers, which have glass transition temperature close to cell culture temperature, may be advantageous for scaffold construction and cell integration. This fact needs to be considered when interpreting data of cell interaction with scaffolds obtained using amorphous polymers developed for 3 D cell culture and tissue engineering applications.

Suppression of ovarian follicle development by nano TiO2 is associated with TGF-β-mediated signaling pathways.

Nanoparticulate titanium dioxide (nano TiO2 ) is extensively applied in biological tissue engineering materials, food additives, cosmetics, and sunscreens. Numerous studies to date have demonstrated that nano TiO2 penetrates through the digestive system and possibly the blood circulation, leading to accumulation in the ovary and consequent reproductive toxicity. However, the mechanisms underlying the toxic effects of nano TiO2 on the female reproductive system remain to be established. In this study, female mice were exposed to different doses of nano TiO2 (1.25, 2.5, or 5 mg/kg body weight) via intragastric administration for 60 consecutive days, followed by investigation of follicular development, regulation of TGF-β-mediated signaling pathways, and expression of the pathway components. Subchronic exposure to nano TiO2 induced a decrease in the number of primordial, secondary, and antral follicles and corpus luteum and concomitant increase in atretic follicles. Furthermore, follicular development disorder induced by nano TiO2 was associated with upregulation of TGF-β1, TGF-βR1, PTEN, and Foxo3a involved in cell growth and apoptosis and downregulation of several growth factors (PI3K, AKT, p-mTOR, p70S6K, p-p70S6K1, rpS6, p-rpS6, TSC1, and TSC2) in mouse ovaries. Our data collectively implied that suppression of ovarian follicle development by nano TiO2 was triggered by dysfunction of the TGF-β, PI3K/AKT/mTOR, and AKT/p70S6K-rpS6/TSC/mTOR pathways. The adverse effects of nano TiO2 on follicular development highlights the necessity for caution in the use of nanomaterials in the food industry. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 414-422, 2019.

Multi-band plasmonic color filters for visible-to-near-infrared image sensors.

We propose a plasmonic color filter consisting of a single aperture surrounded by concentric periodic corrugations for simultaneous imaging of a spectral range from the visible to the near-infrared. The incident light coupled with surface plasmons propagates through the sub-wavelength aperture as beaming light. The beaming light transmission is able to suppress the spatial color cross-talk between the pixels in an image sensor. We analyzed the transmission characteristics of a plasmonic color filter with periodic corrugations in a silver thin film by using the finite-difference time-domain algorithm. We demonstrated a multi-band transmission wavelength selectivity, of about 100 nm, for the spectral bandwidth ranging from visible to near-infrared. The simultaneous discrimination of visible and near-infrared light with a high color purity by the plasmonic color filter achieves both improved image recognition and smaller system-size compared with conventional systems, which is particularly important for applications such as vehicle-mounted cameras, security, and biological tissue engineering.

Graphene and Graphene‐Based Materials in Biomedical Science

AbstractGraphene and its composite materials are very important in many disciplines of science and have been used enormously by researchers since their discovery in 2004. These are a new group of compounds, and are also wonderful model systems for quantum behavior studies. Their properties like exceptional conductivity, biocompatibility, surface area, mechanical strength, and thermal properties make them rising stars in the scientific community. Graphene and its composite compounds are utilized widely in different medical applications, for example, biosensing of biological compounds responsible for disease development, bioimaging of various cells, tissues, microorganisms, animal models, etc. In addition, they are used for enhancing and supporting the stem cell differentiation, i.e., regenerative medicine for regeneration studies of various human organs, tissue engineering in biology for the development of carrier materials, as well as in bone reformation. This review focuses on the modification procedure involved in the fabrication of graphene‐based biomaterials for various applications and recent developments in research related to graphene and graphene‐based materials in biosensing, optical sensing, gas sensing, drug, gene, protein delivery, tissue engineering, and bioimaging. In addition, the potential toxicological effects of graphene‐based biomaterials are discussed.

Electrically controlled water permeation through graphene oxide membranes.

Controlled transport of water molecules through membranes and capillaries is important in areas as diverse as water purification and healthcare technologies1-7. Previous attempts to control water permeation through membranes (mainly polymeric ones) have concentrated on modulating the structure of the membrane and the physicochemical properties of its surface by varying the pH, temperature or ionic strength3,8. Electrical control over water transport is an attractive alternative; however, theory and simulations9-14 have often yielded conflicting results, from freezing of water molecules to melting of ice14-16 under an applied electric field. Here we report electrically controlled water permeation through micrometre-thick graphene oxide membranes17-21. Such membranes have previously been shown to exhibit ultrafast permeation of water17,22 and molecular sieving properties18,21, with the potential for industrial-scale production. To achieve electrical control over water permeation, we create conductive filaments in the graphene oxide membranes via controllable electrical breakdown. The electric field that concentrates around these current-carrying filaments ionizes water molecules inside graphene capillaries within the graphene oxide membranes, which impedes water transport. We thus demonstrate precise control of water permeation, from ultrafast permeation to complete blocking. Our work opens up an avenue for developing smart membrane technologies for artificial biological systems, tissue engineering and filtration.

Wall Shear Stress Determination in a Small-Scale Parallel Plate Flow Chamber Using Laser Doppler Velocimetry Under Laminar, Pulsatile and Low-Reynolds Number Turbulent Flows

The parallel plate flow chamber (PPFC) has gained popularity due to its applications in fields such as biological tissue engineering. However, most of the studies using PPFC refer to theoretical relations for estimating the wall shear stress (WSS) and, hence, the accuracy of such quantifications remains elusive for anything other than steady laminar flow. In the current study, a laser Doppler velocimetry (LDV) method was used to quantify the flow in a PPFC (H = 1.8 mm × W = 17.5 mm, Dh = 3.26 mm, aspect ratio = 9.72) under steady Re = 990, laminar pulsatile (carotid Re0-mean = 282 as well as a non-zero-mean sinusoidal Re0-mean = 45 pulse) and low-Re turbulent Re = 2750 flow conditions. A mini-LDV probe was applied, and the absolute location of the LDV measuring volume with the respect to the wall was determined using a signal monitoring technique with uncertainties being around ±27 μm. The uniformity of the flow across the span of the channel, as well as the WSS assessment for all the flow conditions, was measured with the uncertainties all being less than 16%. At least two points within the viscous sublayer of the low-Re turbulent flow were measured (with the y+ for the first point < 3) and the WSS was determined using two methods with the differences between the two methods being within 5%. This paper for the first time presents the experimental determination of WSS using LDV in a small-scale PPFC under various flow conditions, the challenges associated with each condition, and a comparison between the cases. The present data will be useful for those conducting biological or numerical modeling studies using such devices.

Preparation and biocompatibility of a chitin nanofiber/gelatin composite film

The development of chitin-based materials with favorable mechanical properties and biocompatibility is an important research goal owing to the wide-ranging practical applications. In this study, a composite film was prepared using chitin nanofibers and gelatin. The CNF/gelatin composite film was highly viscous and had a fine nanofiber structure. The transmittances indicated high transparency, regardless of nanofiber content. The water content of the CNF/gelatin composite film increased linearly as the gelatin content increased. Although the CNF/gelatin composite film did not induce severe inflammation, it strongly induced fibroblast proliferation, indicating high biocompatibility. Based on these results, the films are suitable for biological applications, e.g., tissue engineering, medicines, and cosmetics.