The immune-stealth polymeric coating on drug delivery nanocarriers: In vitro engineering and in vivo fate.

Although essential nanosystems such as nanoparticles and nanocarriers are desirable options for transporting various drug molecules into the biological environment, they rapidly remove from the circulatory system due to their interaction with multiple in vivo barriers, especially the immune barrier, which will result in their short-term effects. In order to improve their effectiveness and durability in the circulatory system, the polymer coatings can use to cover the surface of nanoparticles and nanocarriers to conceal them from the immune system. Due to their different properties (like charge, elasticity, and hydrophilicity/hydrophobicity), these coatings can improve drug delivery nanosystem durability and therapeutic applications.

Peroxide mediated oxygen delivery in cancer therapy.

Hypoxia is a serious obstacle in cancer treatment. The aberrant vascular network as well as the abnormal extracellular matrix arrangement results in formation of a hypoxic regions in tumors which show high resistance to the curing. Hypoxia makes the cancer treatment challengeable via two mechanisms; first and foremost, hypoxia changes the cell metabolism and leads the cells towards an aggressive and metastatic phenotype and second, hypoxia decreases the efficiency of the various cancer treatment modalities.

A hydrogel/particle composite with a gradient of oxygen releasing microparticle for concurrent osteogenic and chondrogenic differentiation in a single scaffold.

In the present study, a hydrogel/particle scaffold with a gradient of the oxygen releasing microparticles was developed. Hydrogel component was composed of the oxidized pectin and silk fibroin, whereas the microparticles were constituted from polylactic acid (PLA) and calcium peroxide (CPO). A controlled mixing of the suspensions with different content of the PLA/CPO microparticles conferred a gradient of microparticles in scaffold thickness in a manner that the microparticle content increased with moving from lower to upper face of the composite.

A hydrogel/particle composite with gradient in oxygen releasing microparticle for oxygenation of the cartilage-to-bone interface: Modeling and experimental viewpoints.

At the cartilage-to-bone interface, the residing cells are different with respects to metabolic requirements. Fabrication of a scaffold affording different metabolic needs of these cells can be taken account of a promoting step for regeneration of cartilage- to-bone interface. In the present study, a scaffold with a depth-dependent gradient of oxygen releasing microparticles was developed.

Fabrication of oxygen and calcium releasing microcarriers with different internal structures for bone tissue engineering: Solid filled versus hollow microparticles.

The survival of cells in a three-dimensional scaffold until the ingrowth of blood vessels is an important challenge in bone tissue engineering. Oxygen generating biomaterials can provide the required oxygen and prevent hypoxia in a tissue-engineered scaffold. In this study, poly (L-lactic acid) (PLLA) microspheres loaded with synthesized calcium peroxide (CPO) nanoparticles were fabricated using two different methods, which resulted in hollow and solid filled internal structures.

Development of an oxygen-releasing electroconductive in-situ crosslinkable hydrogel based on oxidized pectin and grafted gelatin for tissue engineering applications.

Injectable hydrogels with conductivity are highly desirable as scaffolds for the engineering of various electrical stimuli-responsive tissues, including nerve, muscle, retina, and bone. However, oxygen deprivation within scaffolds can lead to failure by causing cell necrosis. Therefore, an oxygen release conductive injectable hydrogel can serve as a promising support for the regeneration of such tissues.

Oxygen-releasing nanofibers for breathable bone tissue engineering application.

Oxygen is a vital molecule for cell and tissue processes. Electrospun fibers have been extensively used as drug loading carriers due to possibility of well control over drug release with modulating fiber properties. However, they have not been used as depots for oxygen release.

Fabrication of amine-decorated nonspherical microparticles with calcium peroxide cargo for controlled release of oxygen.

Oxygen is an important signaling molecule which affects many behaviors of bone progenitor cells. Oxygen releasing biomaterials depend on their material and design are able to provide and modulate the desired oxygen for cells. To date, many oxygen releasing vehicles have been developed by incorporating microsized calcium peroxide (CPO) into polymeric matrixes.

A concise review on drug-loaded electrospun nanofibres as promising wound dressings.

The diversity of wound types has gathered momentum to develop a wide range of wound dressings to improve different aspects of the wound healing process. Wound healing is a dynamic, complex and highly regulated mechanism of tissue repair and regeneration. The wound dressing should encourage regeneration and prevent possible infection or scaring.

Engineering of gradient osteochondral tissue: From nature to lab.

The osteochondral tissue is an interface between two distinct tissues: articular cartilage and bone. These two tissues are significantly diverse with regard to their chemical compositions, mechanical properties, structure, electrical properties, and the amount of nutrient and oxygen consumption. Thus, transition from the surface of the articular cartilage to the subchondral bone needs to face several smooth gradients.

On-demand release of ciprofloxacin from a smart nanofiber depot with acoustic stimulus.

Herein, an antibiotic-loaded electrospun scaffold with improved drug delivery via acoustic stimulation has been developed. Ultrasound stimulus with an intensity of 15 W/cm, duty-cycle of 50% and duration of 10 min was repeatedly applied to ciprofloxacin loaded alginate fibers. Ultrasonication with the aforesaid conditions increased drug release from scaffold probably due to disturbance of ionic crosslinks of alginate network.

Particle-coated electrospun scaffold: A semi-conductive drug eluted scaffold with layered fiber/particle arrangement.

In this study, an antibacterial fiber/particle scaffold with improved hydrophilicity has been fabricated. To this end, polyaniline (PANi)/polycaprolactone (PCL) was processed to fibers via electrospinning. Thereafter, ciprofloxacin was loaded in oxidized alginate/gelatin mixture.

A review on gradient hydrogel/fiber scaffolds for osteochondral regeneration.

Osteochondral tissue regeneration is a complicated field due to the distinct properties and healing potential of osseous and chondral phases. In a natural osteochondral region, the composition, mechanics, and structure vary smoothly from bony to cartilaginous phase. Therefore, a homogeneous scaffold cannot satisfy the complexity of the osteochondral matrix.

Hydrogel/fiber conductive scaffold for bone tissue engineering.

Hydrogel/fiber composites have emerged as compelling scaffolds for regeneration purposes. Any biorelated modification or feature may endow more regenerative functionality to these composites. In the present study, a hydrogel/fiber scaffold possessing electrical conductivity in both phases, hydrogel and fiber, has been prepared and evaluated.

Electrically conductive gel/fibers composite scaffold with graded properties.

Gradient biomaterials have emerged as fascinating platforms to satisfy the need for imitation of ubiquitous gradients in biology, especially those found at tissue interfaces. In the current study, a gradient fiber-hydrogel scaffold was fabricated to imitate the extracellular matrix of soft-to-hard tissue interfaces. For the fiber proportion, a gradient electrospinning was developed where controlled mixing of solutions with dissimilar concentration of a conductive polymer in injection vessel imparted a composition gradient to electrospinning jet, and thus electrospun fibers.

A review of key challenges of electrospun scaffolds for tissue-engineering applications.

Tissue engineering holds great promise to develop functional constructs resembling the structural organization of native tissues to improve or replace biological functions, with the ultimate goal of avoiding organ transplantation. In tissue engineering, cells are often seeded into artificial structures capable of supporting three-dimensional (3D) tissue formation. An optimal scaffold for tissue-engineering applications should mimic the mechanical and functional properties of the extracellular matrix (ECM) of those tissues to be regenerated.