Enthesis Healing Is Dependent on Scaffold Interphase Morphology-Results from a Rodent Patellar Model.

The use of multiphasic scaffolds to treat injured tendon-to-bone entheses has shown promising results in vitro. Here, we used two versions of a biphasic silk fibroin scaffold to treat an enthesis defect created in a rat patellar model in vivo. One version presented a mixed transition between the bony and the tendon end of the construct (S-MT) while this transition was abrupt in the second version (S-AT).

Microfluidic-assisted electrospinning, an alternative to coaxial, as a controlled dual drug release system to treat inflammatory arthritic diseases.

Inflammatory arthritic diseases are characterized by a persistent inflammation of the synovial tissues where tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) pro-inflammatory cytokines are over-expressed, leading to progressive musculoskeletal disability. Methotrexate (MTX), a disease-modifying-anti-rheumatic drug (DMARD) commonly applied in their treatment, can be used in combination with biological-DMARDs as anti-TNFα antibody to improve the treatments efficacy. However, their systemic administration comes with severe side-effects and limited therapeutic efficacy due to their off-target distribution and short half-life.

Development of alginate-based hydrogels for blood vessel engineering.

Vascular diseases are among the primary causes of death worldwide. In serious conditions, replacement of the damaged vessel is required. Autologous grafts are preferred, but their limited availability and difficulty of the harvesting procedures favour synthetic alternatives' use.

Silk-Based Matrices and c-Kit-Positive Cardiac Progenitor Cells for a Cellularized Silk Fibroin Scaffold: Study of an in vivo Model.

The production of a cellularized silk fibroin scaffold is very difficult because it is actually impossible to differentiate cells into a well-organized cardiac tissue. Without vascularization, not only do cell masses fail to grow, but they may also exhibit an area of necrosis, indicating a lack of oxygen and nutrients. In the present study, we used the so-called tyrosine protein kinase kit (c-Kit)-positive cardiac progenitor cells (CPCs) to generate cardiac cellularized silk fibroin scaffolds, multipotent cells isolated from the adult heart to date that can show some degree of differentiation toward the cardiac phenotype.

Preparation and evaluation of gellan gum hydrogel reinforced with silk fibers with enhanced mechanical and biological properties for cartilage tissue engineering.

Various research about cartilage regeneration using biomaterials has been done recently. Particularly, gellan gum hydrogel (GG) is reported to be suitable as a biomaterial for cartilage tissue engineering (TE) for its water uptaking ability, producibility, and environmental resemblance of native cartilage. Despite these advantages, mechanical and cell adhesion properties are still difficult to modulate.

Multinucleated Giant Cells Induced by a Silk Fibroin Construct Express Proinflammatory Agents: An Immunohistological Study.

Multinucleated giant cells (MNGCs) are frequently observed in the implantation areas of different biomaterials. The main aim of the present study was to analyze the long-term polarization pattern of the pro- and anti-inflammatory phenotypes of macrophages and MNGCs for 180 days to better understand their role in the success or failure of biomaterials. For this purpose, silk fibroin (SF) was implanted in a subcutaneous implantation model of Wistar rats as a model for biomaterial-induced MNGCs.

A novel and selective silk fibroin fragmentation method.

In the tissue-engineering field silk fibroin can be tailored to the target applications by modifying its secondary structure and molecular weight, and functionalizing the molecule with specific active groups linked to the amino acid side chains. To better tune the silk fibroin molecular weight and structural properties, we propose the creation of a lower molecular weight fibroin-derived material through a selective and tunable enzymatic attack on the fibroin chain. Cleavage at specific amino acid sites leads to precise silk fibroin fragmentation and, thus, lower molecular weight materials whose length and properties can be tuned with the enzyme concentration.

Injectable Scaffold-Systems for the Regeneration of Spinal Cord: Advances of the Past Decade.

Nowadays, whenever is possible and as an alternative to open spine surgery, minimally invasive procedures are preferred to treat spinal cord injuries (SCI), with percutaneous injections or small incisions, that are faster, less traumatic, and require less recovery time. Injectable repair systems are based on materials that can be injected in the lesion site, can eventually be loaded with drugs or even cells, and act as scaffolds for the lesion repair. The review analyzes papers written from 2010 onward on injectable materials/systems used/proposed for the regenerative and combinatorial therapies of SCI and discusses the models that have been used to validate them.

A Bio-inspired Multifunctionalized Silk Fibroin.

A bio-inspired multifunctionalized silk fibroin (BMS) was synthesized in order to mimic the interaction of nidogen with the type IV collagen and laminin of basement membranes. The designed BMS consists of a motif of laminin α-chain-derived, called IK peptide, and type IV collagen covalently bound to the silk fibroin (SF) by using EDC/NHS coupling and a Cu-free click chemistry reaction, respectively. Silk fibroin was chosen as the main component of the BMS because it is versatile and biocompatible, induces an favorable bioresponse, and moreover can be functionalized with different methods.

Natural Fibrous Protein for Advanced Tissue Engineering Applications: Focusing on Silk Fibroin and Keratin.

As one of the important branches of natural biopolymer, natural fibrous protein has a lot of advantages including good mechanical properties, excellent biocompatibility, controllable biodegradability, renewability, abundant sources, and so on. Moreover, natural fibrous protein is also a protein that could only be used for structure supporting without any bioactivities, which attracts a lot of attentions in the field of tissue engineering scaffold. This chapter is taking silk fibroin and keratin as model materials of natural fibrous protein, focusing on their protein structure, chemical compositions, processing and extraction methods, chemical modification methods, and their applications in tissue engineering through advanced manufacturing.

Spider (Linothele megatheloides) and silkworm (Bombyx mori) silks: Comparative physical and biological evaluation.

Silks, in particular silkworm silks, have been studied for decades as possible candidate materials for biomedical applications. Recently, great attentions have been paid to spider silks, mainly due to their unique and remarkable mechanical properties. Both materials express singular interactions with cells through specific biorecognition moieties on the core proteins making up the two silks.

Injectable taurine-loaded alginate hydrogels for retinal pigment epithelium (RPE) regeneration.

The purpose of this study is to produce injectable taurine (Tr)-loaded alginate (Agn) hydrogel for age-related macular degeneration (AMD) treatment by inducing the regeneration of RPE (retinal pigment epithelium) cells. Porosity and swelling ratio were measured to evaluate the mechanical properties of the hydrogels, and Fourier transform infrared spectroscopy (FTIR) was used to evaluate the physical and chemical properties. RPE cells extracted from the pigmented epithelium of rabbits were encapsulated in the Tr/Agn hydrogels.

Synthesis of Gold Nanoparticles Decorated with Multiwalled Carbon Nanotubes (Au-MWCNTs) via Cysteaminium Chloride Functionalization.

Gold nanoparticles (AuNPs) decorated CNTs are promising materials for photocatalytics and biosensors. However, the synthesis of AuNPs chemically linked to the walls of MWCNTs is challenging and toxic products such as thionylchloride (SOCl) or [1-ethyl-3(dimethyl-amino) propyl] carbodiimide hydrochloride (EDAC) need to be used. This work reports a new approach to prepare gold nanoparticles decorated multiwalled carbon nanotubes (MWCNTs) by using cysteaminium chloride via the formation of a Zwitterionic acide-base bond.

Breath Figures decorated silicon oxinitride ceramic surfaces with controlled Si ions release for enhanced osteoinduction.

Bioactive coatings are usually applied to bone and dental prostheses to enhance the integration and their stability in the bone. Recently, silicon (Si) oxynitride ceramics have been demonstrated to possess osteoconductive properties due to the release of Si ions, particularly important in the early stage of bone formation. In addition, the pattern of the bone contacting surface has been reported to affect cells' differentiation and metabolic activity.

Theranostic gold-magnetite hybrid nanoparticles for MRI-guided radiosensitization.

The main limitation of drug-enhanced radiotherapy concerns the difficulty to evaluate the effectiveness of cancer targeting after drug administration hindering the standardization of therapies based on current radiosensitizing compounds. The challenge regards the development of systems able to combine imaging and radiotherapy enhancement in order to perform highly reliable cancer theragnosis. For these reasons, gold-magnetite hybrid nanoparticles (H-NPs) are proposed as innovative theranostic nanotools for imaging-guided radiosensitization in cancer treatment.

Sodium oleate induced rapid gelation of silk fibroin.

Silk fibroin has acquired increasing interest in the last years for application in medicine and namely in tissue engineering. Several methods have been developed to process fibroin and for the fabrication of nets, sponges, films and gels. This paper deals with the fabrication and characterization of fibroin hydrogels obtained by using sodium oleate as gelation agent.

Heparin functionalization increases retention of TGF-β2 and GDF5 on biphasic silk fibroin scaffolds for tendon/ligament-to-bone tissue engineering.

Unlabelled: The tendon/ligament-to-bone transition (enthesis) is a highly specialized interphase tissue with structural gradients of extracellular matrix composition, collagen molecule alignment and mineralization. These structural features are essential for enthesis function, but are often not regenerated after injury. Tissue engineering is a promising strategy for enthesis repair.

Silk fibroin porous scaffolds by NO foaming.

Silk fibroin has acquired increasing interest for biomedical applications, and namely for the fabrication of scaffolds for tissue engineering, because of its highly positive biological interaction and the possibility to adapt the material to several application requirements by adopting different fabrication methods, in order to make films, sponges, fibers, nets or gels with predictable degradation times. For tissue engineering, in most cases porous scaffolds are required, in some cases possibly in situ forming and therefore fabricated in mild body-compatible conditions. In this work, we present a novel one-step method for the preparation of silk fibroin foams starting from water solutions and using low-pressure nitrous oxide gas as foaming agent.

Homeostasis maintenance of encapsulated cells.

Cell niche homeostasis plays a critical role in many bodily functions including tissue functionality, stem cell maintenance and differentiation, wound healing, cancer development and propagation, and many others. Many tissue engineering approaches overlook the importance of engineered constructs homeostasis, in particular for transplantation purposes. Here, we present a study of the effect of encapsulation duration on engineered tissue maturation and provide a protocol for the evaluation of critical conditions for transplantation purposes.

Effect of Cryopreservation on Cell-Laden Hydrogels: Comparison of Different Cryoprotectants.

Cell encapsulation in hydrogels is a technique that offers a variety of applications, ranging from drug delivery to biofabrication of three-dimensional scaffolds. The assembly of cell-laden hydrogel building blocks aims to generate complex biological constructs by manipulating microscale units. An important issue for the clinical implementation of this technique is the long-term storage of a large stock of cell/hydrogel building blocks.

Plasma assisted surface treatments of biomaterials.

The biocompatibility of an implant depends upon the material it is composed of, in addition to the prosthetic device's morphology, mechanical and surface properties. Properties as porosity and pore size should allow, when required, cells penetration and proliferation. Stiffness and strength, that depend on the bulk characteristics of the material, should match the mechanical requirements of the prosthetic applications.

Bioactivity and mineralization of natural hydroxyapatite from cuttlefish bone and Bioglass co-sintered bioceramics.

In this study, bioactive hydroxyapatite (HAP)-based bioceramics starting from cuttlefish bone powders have been prepared and characterized. In particular, fragmented cuttlefish bone was co-sintered with 30 wt% of Bioglass -45S5 to synthesize HAP-based powders with enhanced mechanical properties and bioactivity. Commercial synthetic HAP was treated following the same procedure and used as a reference.

Fabrication and Characterization of Biphasic Silk Fibroin Scaffolds for Tendon/Ligament-to-Bone Tissue Engineering.

Tissue engineering is an attractive strategy for tendon/ligament-to-bone interface repair. The structure and extracellular matrix composition of the interface are complex and allow for a gradual mechanical stress transfer between tendons/ligaments and bone. Thus, scaffolds mimicking the structural features of the native interface may be able to better support functional tissue regeneration.

Enhancing bioactive properties of silk fibroin with diatom particles for bone tissue engineering applications.

Many studies have highlighted the role of silicon in human bone formation and maintenance. Silicon, in fact, is considered to nucleate the precipitation of hydroxyapatite and to reduce the bone resorption. For this reason, we have combined silk fibroin (SF) with silicon-releasing diatom particles (DPs), as potential material for bone tissue engineering applications.

From honeycomb- to microsphere-patterned surfaces of poly(lactic acid) and a starch-poly(lactic acid) blend via the breath figure method.

Background: This study investigated the preparation of ordered patterned surfaces and/or microspheres from a natural-based polymer, using the breath figure and reverse breath figure methods.

Methods: Poly(D,L-lactic acid) and starch poly(lactic acid) solutions were precipitated in different conditions - namely, polymer concentration, vapor atmosphere temperature and substrate - to evaluate the effect of these conditions on the morphology of the precipitates obtained.

Results: The possibility of fine-tuning the properties of the final patterns simply by changing the vapor atmosphere was also demonstrated here using a range of compositions of the vapor phase.