Wednesday, 18 July 2018

Supramolecular Biomaterials in kidney regeneration and replacement strategies :

The kidney is the primary organ involved in the filtration and excretion of waste, and toxic compounds from the blood. The nephron is the kidney’s functional component which is damaged or impaired in most renal diseases. In the Dutch population around 11% is suffering of mild to severe renal disease, with an increasing prevalence as the population ages.
As of yet there are only two treatment options for end stage kidney disease; dialysis, and kidney transplantation. Both options are far from ideal. Dialysis requires frequent visits to the clinic, and is incapable of clearing protein bound uremic toxins. Organ transplantation is limited by donor shortage, acute rejection, and a lifelong need for immunosuppressive therapy. Therefore, improvements are needed in kidney regeneration and replacement strategies.
In our previous research we have shown that supramolecular biomaterials can be created, mimicking the renal basement membrane. It was shown that these biomaterials are able to control in-vitro functioning of renal epithelial cells. Important in the further development of functional biomaterials, is their interaction with cells via bioactive functionalities, such as peptides. In the current research we aim at resolving the interactions of the cell with the bioactive supramolecular biomaterial at a microscopic and molecular level. Combination of these insights with established renal cell function assays is proposed to gain fundamental insights in renal cell behavior on supramolecular surfaces. This is proposed to lead to the development of materials that can be applied to ameliorate dialysis and possibly to in-situ regenerate renal tissue.

Monday, 16 July 2018

DNA delivery from polymer matrices for Tissue Engineering : 

Engineered tissues by the incorporation and sustained release of plasmids encoding tissue-inductive proteins from polymer matrices. Matrices of poly(lactide-co-glycolide) (PLG) were loaded with plasmid, which was subsequently released over a period ranging from days to a month in vitro. Sustained delivery of plasmid DNA from matrices led to the transfection of large numbers of cells. Furthermore, in vivo delivery of a plasmid encoding platelet-derived growth factor enhanced matrix deposition and blood vessel formation in the developing tissue. This contrasts with direct injection of the plasmid, which did not significantly affect tissue formation. This method of DNA delivery may find utility in tissue engineering and gene therapy applications.

Monday, 9 July 2018

Bladder Biomechanics and the use of Scaffolds for Regenerative Medicine in the Urinary Bladder : 

The urinary bladder is a complex organ with the primary functions of storing urine under low and stable pressure and micturition. Many clinical conditions can cause poor bladder compliance, reduced capacity, and incontinence, requiring bladder augmentation or use of regenerative techniques and scaffolds. To replicate an organ that is under frequent mechanical loading and unloading, special attention towards fulfilling its biomechanical requirements is necessary. Several biological and synthetic scaffolds are available, with various characteristics that qualify them for use in bladder regeneration in vitro and in vivo, including in the treatment of clinical conditions. The biomechanical properties of the native bladder can be investigated using a range of mechanical tests for standardized assessments, as well as mathematical and computational bladder biomechanics. Despite a large body of research into tissue engineering of the bladder wall, some features of the native bladder and the scaffolds used to mimic it need further elucidation.

Thursday, 5 July 2018

Characteristics and applications of titanium oxide as a Biomaterial for medical implants : 


There is considerable interest in TiO2 for a wide range of applications; however, it mainly focuses on its uses as a biomaterial, particularly for biomedical implant devices. The main characteristics required for this application have been considered. Methods for producing TiO2 and Ag doped TiO2 films are summarized. The interactions of the films containing body fluids, mainly with blood components such as proteins, are discussed. Various techniques, including surface analysis methods, have been employed to characterize the undoped and Ag doped TiO2 films. Their behaviour under normal conditions inside the body, such as physiological pH, has been investigated.


Tuesday, 3 July 2018

Biomaterials for Wound healing : 


The advantageous biocompatibility and cell proliferative effects of synthetic and natural biomaterials have promoted their broad use in various medical areas, including wound healing. Most synthetic biomaterials show excellent physical properties but are, in general, complicated to fabricate, whereas natural biomaterials normally show no cell toxicity or elicit foreign body responses but show high natural variability. Existent biomaterials used for wound healing purposes, the naturally obtained categories such as polysaccharide-based, protein-based, nanofiber-based, and marine biomaterials, which have been investigated in depth in vivo and in clinical studies.

Monday, 2 July 2018

Surface modification of Biomaterials by heparinisation to improve Blood Compatibility : 


Blood compatibility is mainly influenced by the surface properties of the materials. The interaction of the surface and blood leads to a blood coagulation which is not desirable for some medical applications. In order to create a blood compatible material with an anti-thromobogenic or non-thromobogenic surface, many theoretical hypotheses have been postulated. In practice, surface modification by utilisation of heparin is one of the mostly widely accepted approaches for improvement of blood compatibility. In this chapter, some of the immobilisation methodologies are reviewed and the effects of heparinisation on blood compatibility both in vitro and in vivo are also assessed including protein adsorption, platelet adhesion, thrombus formation and other factors which influence blood compatibility.


Saturday, 30 June 2018

Hybrid laser technology for Biomaterials : 

Biomaterials are used for the reparation or reconstruction of the musculo-skeletal system and soft tissue regeneration as well as in various medical instruments and devices. The potential range of applications for biomaterials is rapidly increasing, with different physical, mechanical and medical properties required for different applications. One flexible and widely used method for the fast preparation and testing of biomaterials is pulsed laser deposition (PLD). The use of PLD for biomaterials and improvements to the technique that will allow the fabrication of materials with very specific biocompatible properties. Some practical applications of PLD and hybrid PLD in the field of biomaterials.


Friday, 29 June 2018

Biomaterials for Cell Targeting :


Cell targeting is an interesting prospect for drug delivery because it offers a potential avenue for drug optimization, as well as opening the possibility of the development of new drug therapies. Biomaterials can be a potential prospect because the properties of the compounds inherent to the biomaterials can be harnessed to be directed by the body to the cell of interest. Polymers, from buckminsterfullerenes to nanofibers, can be altered to contain side-chains that will interact with certain cell surface receptors, and metals can be used in conjunction with organic compounds to give interesting properties to otherwise inert compounds, as in the case of metallofullerenes.
Cell targeting is an interesting prospect for drug delivery because it offers a potential avenue for drug optimization, as well as opening the possibility of the development of new drug therapies. Biomaterials can be a potential prospect because the properties of the compounds inherent to the biomaterials can be harnessed to be directed by the body to the cell of interest. Polymers, from buckminsterfullerenes to nanofibers, can be altered to contain side-chains that will interact with certain cell surface receptors, and metals can be used in conjunction with organic compounds to give interesting properties to otherwise inert compounds, as in the case of metallofullerenes.

Thursday, 28 June 2018

Nanofabricated Scaffolds : 

While critical insights into 2D cell-nanotopography interactions are now enabling us to direct cell behavior, considerable efforts have been made to develop 3D artificial scaffolds at the nanoscale for tissue engineering applications. Nanofibrous scaffolds are now under wide investigation as they exhibit a very similar physical structure to protein nanofibers in ECM. Among the three dominant nanofabrication methods, electrospinning is a very simple and practical technique, suitable for the creation of aligned and complex 3D structures; self-assembly technology emulates the process of ECM assembly and can thus produce very thin nanofibers; and phase separation allows for continuous fiber network fabrication with tunable pore structure, and the formation of sponge-like scaffolding. Nanocomposites based scaffolds (e.g. nano-hydroxyapatite/collagen) are, on the other hand, very popular in hard-tissue engineering, particularly for the reconstruction of bone tissue. Beyond nanofibers and nanocomposites, carbon nanotubes have also attracted attention due to their mechanical strength and electrical conductivity, and because they can be readily incorporated into 3D architectures.


Tuesday, 26 June 2018

MEM/NEM devices for drug delivery : 


The field of micro-/nanoelectromechanical (MEM/NEM) device-based drug delivery has also made significant headway over the past decade. In particular, implantable microchips containing nanosized reservoirs have been developed to deliver drugs for long time periods in a precisely controlled manner; microneedles are being tested in painless transdermal drug delivery; and the incorporation of nanofeatures (e.g. nanopores, nanochannels, and nanoparticles) in microfabricated systems are perfecting drug delivery and immunoisolation techniques. Intriguingly, these devices can be further modified to deliver new therapeutics, achieve targeted delivery, and co-deliver multiple agents. Substantial efforts are also being put into creating intelligent devices that could potentially sense when and how much dose is needed and then automatically release it from reservoirs. To do this, one feat that must be met is the continuous and stable monitoring of physical and biochemical conditions, in situ. The recent development of nanotechnology-based sensors (e.g. nanowire and nanotube) may offer new ways to address this concern, and could even facilitate device miniaturization.


Friday, 22 June 2018

Cell-Nanotopography Interactions : 


Living cells are highly sensitive to local nanoscale topographic patterns within ECM. In the pursuit to control cell function by underlying nanotopographic cues, engineered substrates with different nanofeatures have become rapidly adopted. Top-down lithographic techniques are now utilized to create various nanopatterns, such as gratings, pillars, and pits, in a precisely controlled manner. Techniques like micelle lithography, anodization, and electrospinning can also be used to create an array of nanospheres, vertical nanotubes, and nanofibers. Additionally, less-ordered nanotopographies are now being fabricated by polymer demixing, chemical etching, electrospinning, and phase separation processes.


Thursday, 21 June 2018

Nanotechnology in Drug Delivery and Tissue Engineering

Nanotechnology in Drug Delivery and Tissue Engineering : 

The application of nanotechnology in medicine, referred to as nanomedicine, is offering numerous exciting possibilities in healthcare.

Drug delivery
Nanoscale delivery vehicles can (1) enhance the therapeutic efficacy and minimize adversities associated with available drugs; (2) enable new classes of therapeutics; and (3) encourage the re-investigation of pharmaceutically suboptimal but biologically active new molecular entities that were previously considered undevelopable.

Tissue engineering
Nanotechnology can enable the design and fabrication of biocompatible scaffolds at the nanoscale and control the spatiotemporal release of biological factors—resembling native extracellular matrix—to direct cell behaviors, and eventually lead to the creation of implantable tissues.

Tuesday, 19 June 2018

Applications of Nanoengineered scaffolds in Tissue growth and Regenerative medicine:


It is becoming increasingly evident that interaction between cells and their microenvironment at the nanoscale level can reorganize cytoskeleton and induce specific cell signaling that regulates the fate of the cell. Thus, nanostructured scaffolds that mimic the tissue-specific microenvironment have been of great interest in nanotechnology for tissue engineering and regenerative medicine. Scaffolds with biochemical, mechanical, and electrical properties similar to those of native tissues have been nanoengineered to enhance cell adhesion, proliferation, differentiation, and even maturation, thereby fostering cell function and tissue growth.

An extracellular matrix-like architecture can be fabricated by nanopatterning, electrospinning, self-assembly, conjugation of adhesion motifs to the matrix backbone, or sulfating the matrix backbone. The properties of this extracellular matrix-like architecture can be adjusted by incorporation of nanomaterials such as carbon nanotubes, nanowires, and nanoparticles. For instance, developed an electrically conductive hybrid hydrogel scaffold based on gold nanoparticles homogeneously synthesized throughout a polymer template gel. The expression of connexin-43 increased in neonatal cardiomyocytes grown on the scaffold, suggesting that an electrically active scaffold impregnated with gold can enhance cardiomyocyte function.