Cellulose nanocrystals-reinforced dual crosslinked double network GelMA/hyaluronic acid injectable nanocomposite cryogels with improved mechanical properties for cartilage tissue regeneration.

Improvement of mechanical properties of injectable tissue engineering scaffolds is a current challenge. The objective of the current study is to produce a highly porous injectable scaffold with improved mechanical properties. For this aim, cellulose nanocrystals-reinforced dual crosslinked porous nanocomposite cryogels were prepared using chemically crosslinked methacrylated gelatin (GelMA) and ionically crosslinked hyaluronic acid (HA) through the cryogelation process.

Polysaccharide-based polyampholyte complex formation: Investigating the role of intra-chain interactions.

The difference in inter-chain and intra-chain electrostatic attraction was investigated in polyelectrolyte and polyampholyte electrostatic complex formation. Three polymers with similar backbone molecular structures including chitosan (Ch) polycation, carboxymethyl cellulose (CMCe) polyanion, and carboxymethyl chitosan (CMCh) polyampholyte were used for this purpose. The turbidimetric, water content, and rheological measurements for polyampholyte self-complex showed more dependence on the ionic strength rather than the polyelectrolyte one.

Shape memory injectable cryogel based on carboxymethyl chitosan/gelatin for minimally invasive tissue engineering: In vitro and in vivo assays.

Shape-memory cryogels have drawn attention as an injectable system to minimize the risks associated with surgical implantation in tissue engineering. To achieve shape memory behavior with hydration as an external stimulus, it is necessary to have a porous elastic network. To achieve this, it is crucial to control the crosslinking process at the time of pore formation, especially for natural-based polymers.

A highly efficient microwave-assisted synthesis of an LED-curable methacrylated gelatin for bio applications.

This study deals with the development of an LED-curable methacrylated gelatin (GelMA) synthesis microwave (MW) irradiation with a reaction and purification time-, energy-, and methacrylation reagent-saving approach. To investigate the efficiency of MW irradiation in GelMA synthesis, characteristics of the GelMAs prepared by using glycidyl methacrylate (GMA) or methacrylic anhydride (MA) the MW-assisted (MWA) method were compared comprehensively with those synthesized the conventional heating method. Moreover, MWA reaction conditions were optimized in terms of methacrylation reagent concentrations (), reaction time (), and MW power ().

Injectable hydrogels for bone and cartilage tissue engineering: a review.

Tissue engineering, using a combination of living cells, bioactive molecules, and three-dimensional porous scaffolds, is a promising alternative to traditional treatments such as the use of autografts and allografts for bone and cartilage tissue regeneration. Scaffolds, in this combination, can be applied either through surgery by implantation of cell-seeded pre-fabricated scaffolds, or through injection of a solidifying precursor and cell mixture, or as an injectable cell-seeded pre-fabricated scaffold. In situ forming and pre-fabricated injectable scaffolds can be injected directly into the defect site with complex shape and critical size in a minimally invasive manner.

FeO nanoparticles coated with carboxymethyl chitosan containing curcumin in combination with hyperthermia induced apoptosis in breast cancer cells.

Many studies have demonstrated that curcumin has potential anticancer properties. This research aims to study the effect of iron (II, III) oxide (FeO) nanoparticles coated with carboxymethyl chitosan containing curcumin combination with hyperthermia on breast cancer cells. Magnetic nanoparticles coated with carboxymethyl chitosan containing curcumin (MNP-CMC-CUR) were prepared and specified.

Chitosan/PVA/Doxycycline Film and Nanofiber Accelerate Diabetic Wound Healing in a Rat Model.

In this study, we evaluated the effects of nanofiber and film polymers with doxycycline for treating a wound in a diabetic rat model. 108 male rats were divided into six groups, the control group, the diabetic control, and the groups were diabetic rats receiving different wound dressing. At the 3rd, 7th, and 14th days, macroscopic/histologic imaging and tissue sampling were performed.

Injectable and reversible preformed cryogels based on chemically crosslinked gelatin methacrylate (GelMA) and physically crosslinked hyaluronic acid (HA) for soft tissue engineering.

Hydrogels are a promising choice for soft tissue (cartilage, skin and adipose) engineering and repair. However, lack of interconnected porosity and poor mechanical performance have hindered their application, especially in natural polymer-based hydrogels. Cryogels with the potential to overcome the shortcomings of hydrogels have drawn attention in the last few years.

Fabrication of nanocomposite/nanofibrous functionally graded biomimetic scaffolds for osteochondral tissue regeneration.

One of the main challenges in treating osteochondral lesions via tissue engineering approach is providing scaffolds with unique characteristics to mimic the complexity. It has led to application of heterogeneous scaffolds as a potential candidate for engineering of osteochondral tissues, in which graded multilayered-structure should promote bone and cartilage growth. By designing three-dimensional (3D)-nanofibrous scaffolds mimicking the native extracellular matrix's nanoscale structure, cells can grow in controlled conditions and regenerate the damaged tissue.

Semi-IPN Films and Electrospun Nanofibers Based on Chitosan/PVA as an Antibacterial Wound Dressing.

The antimicrobial activity of a wound dressing is a key factor for preventing and treating wound infection. The current study evaluated the physiochemical properties and antimicrobial activities of semi-IPNs (interpenetrating polymer networks) based on chitosan/polyvinyl alcohol (PVA) films and nanofibers as candidates for wound dressings and investigated the effects of morphologies (nanofibrous mats and films), crosslinking conditions of chitosan chains (uncrosslinked and crosslinked with genipin), and the presence of antibacterial drug (doxycycline) on their physicochemical and antibacterial properties. The morphology, chemical structure, fluid uptake, water vapor transmission rate, antimicrobial activity, and doxycycline release profile were assayed using SEM, FTIR spectroscopy, swelling test, permeation test, agar diffusion antibiogram, and dissolution test, respectively.

Mechanical Characteristics of SPG-178 Hydrogels: Optimizing Viscoelastic Properties through Microrheology and Response Surface Methodology.

Background: Self-assembling peptides (SApeptides) have growing applications in tissue engineering and regenerative medicine. The application of SApeptide-based hydrogels depends strongly on their viscoelastic properties. Optimizing the properties is of importance in tuning the characteristics of the hydrogels for a variety of applications.

3D in vitro cancerous tumor models: Using 3D printers.

Recently, magnetic Hyperthermia is one of the promising methods for cancer treatments. In this method by applying magnetic fields and generating heat, cancerous tissues are eliminated. The degree and pattern of generated heat in cancerous and adjacent non-cancerous tissues plays an important role on the outcome of the treatment.

On the analysis of microrheological responses of self-assembling RADA16-I peptide hydrogel.

This work aims to obtain a hydrogel based on self-assembling RADA16-I with proper rheological properties for hemostasis application. Response surface methodology (RSM) was performed to predict the gelation and stiffness of the hydrogel in different concentrations of peptide and NaCl in water and blood serum milieus. Particle tracking microrheology technique was used to evaluate Brownian motion of polystyrene particles in the peptide solutions to obtain their trajectories and measure the viscoelastic properties (G'', G″, and tan δ).

Chitosan/polyethylene glycol fumarate blend films for wound dressing application: in vitro biocompatibility and biodegradability assays.

Blending is one of the effective approaches in preparing tailored materials with a wide range of properties. Thus, chitosan-based polymers have been fabricated and used as wound dressings since they possess better properties than those of the constituent materials. The objective of this work was to evaluate the biocompatibility and biodegradability of biodegradable blend films based on polyethylene glycol-co-fumarate (PEGF) and chitosan (Ch).

Combinational drug delivery using nanocarriers for breast cancer treatments: A review.

Breast cancer (BC) is the most common cancer in women that requires special attention due to low response to conventional treatments. The common method for treating cancer (especially BC) is applying a single anticancer agent, however, due to some disadvantages including cytotoxicity, side effects, and multidrug resistance, the efficiency and application of this method are limited. To overcome these challenges, the combinational delivery of anticancer drugs (including chemical agents, genetic materials, etc.

Effect of electrospinning parameters on morphological properties of PVDF nanofibrous scaffolds.

Smart materials like piezoelectric polymers represent a new class of promising scaffold in neural tissue engineering. In the current study, the fabrication processing parameters of polyvinylidine fluoride (PVDF) nanofibrous scaffold are found as a potential scaffold with nanoscale morphology and microscale alignment. Electrospinning technique with the ability to mimic the structure and function of an extracellular matrix is a preferable method to customize the scaffold features.

Biodegradable microrobots for targeting cell delivery.

These days, cell delivery is considered a potential method for treatment of many genetic diseases or tissue regeneration applications. In conventional cell delivery methods, cells are encapsulated in or cultured on biocompatible polymers. However, the main problem with these carriers is their lack of targeting ability.

Piezoelectric electrospun nanocomposite comprising Au NPs/PVDF for nerve tissue engineering.

In this study, gold nanoparticles/Polyvinylidenefluoride (PVDF) composite electrospun mat with enhanced piezoelectricity were fabricated and characterized. Gold colloidal nanoparticles (Au NPs) were prepared via laser ablation of metallic targets in liquid media. The active Q-switched Nd:YAG laser was used as an irradiation source.

Fabrication of cancellous biomimetic chitosan-based nanocomposite scaffolds applying a combinational method for bone tissue engineering.

The aim of this study was to mimic the specific structure of bone and fabricate a biomimetic nano-hydroxyapatite (HA)/chitosan (Cs)/gelatin scaffolds using combination of particle leaching and freeze drying methods eliminating mold effects. To achieve an optimum structure, scaffolds with different gelatin/Cs weight ratio were fabricated. Morphological characterization of scaffolds by scanning electron microscopy method showed highly interconnected porous structures similar to cancellous bone with mean pore size ranging from 140 to 190 μm.

Particle size modeling and morphology study of chitosan/gelatin/nanohydroxyapatite nanocomposite microspheres for bone tissue engineering.

In this study, nanocomposite microspheres based on chitosan/gelatin/nanohydroxyapatite were fabricated, and effects of the nanohydroxyapatite/biopolymer (chitosan/gelatin) weight ratio (nHA/P), stirring rate, chitosan concentration and biopolymer concentration on the particle size, and morphology of nanocomposite microspheres were investigated. Particle size of microspheres was modeled by design of experiments using the surface response method. Particle size, morphology of microspheres, and distribution of nanoparticles within the composite microspheres were evaluated using an optical microscope, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively.

Polystyrene surface modification using excimer laser and radio-frequency plasma: blood compatibility evaluations.

Biomaterial surface modification is an efficient method to improve and control blood component-material interactions. In the present study, two different methods (ArF excimer laser irradiation and radio-frequency (RF) plasma treatment) were applied in separate procedures to create a vast range of physicochemical characteristics on the surface of polystyrene (PS) and investigate their effects on blood compatibility of treated surfaces. Atomic force microscopy (AFM) and Fourier transmission infrared analysis were applied to study the morphology and chemical characteristics of treated samples in comparison with those of the untreated PS.

Hydroxyapatite scaffolds infiltrated with thermally crosslinked polycaprolactone fumarate and polycaprolactone itaconate.

In this work, two unsaturated derivatives of polycaprolactone (PCL), polycaprolactone fumarate (PCLF), and polycaprolactone itaconate (PCLI), have been synthesized and used as an infiltrating polymer to improve the mechanical properties of brittle hydroxyapatite (HA) scaffolds. PCLF and PCLI were first synthesized through polyesterification of the low molecular weight PCL diols with fumaryl chloride and itaconyl chloride respectively, and then characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, and differential scanning calorimetry analysis. HA scaffolds were sintered using a foam replication technique, with porosity of about 60%.