3D printed PCL-nHAp composite implants for the treatment of segmental bone defects: in vivo application in a rabbit model.

The management and treatment of long bone defects are challenging clinical problems. In this study, in order to address the need for load bearing segmental defects, 3D printed cylindrical implants of poly(-caprolactone) (PCL) and nanohydroxyapatite (nHAp) composites were prepared and applied as lateral segments to the femurs of New Zealand white rabbits. The results obtained after 6 weeks of implantation were compared with the autografts.

MgCa-Based Alloys Modified with Zn- and Ga-Doped CaP Coatings Lead to Controlled Degradation and Enhanced Bone Formation in a Sheep Cranium Defect Model.

Mg-based biodegradable metallic implants are gaining increased attraction for applications in orthopedics and dentistry. However, their current applications are hampered by their high rate of corrosion, degradation, and rapid release of ions and gas bubbles into the physiological medium. The aim of the present study is to investigate the osteogenic and angiogenic potential of coated Mg-based implants in a sheep cranial defect model.

Zn doped CaP coatings used for controlling the degradation rate of MgCa1 alloy: In vitro anticorrosive properties, sterilization and bacteria/cell-material interactions.

The purpose of this study was to investigate the effect of Zn doped CaP coatings prepared by micro-arc oxidation method, as a possible approach to control MgCa1 alloy degradation. All the prepared coatings comprised a calcium deficient CaP phase. The control in this evaluation was performed with undoped CaP coating in SBF solution at body temperature (37 ± 0.

LOCAL-IGF-1 and GH application IMPROVES germ cell histology, spermatogenesis and fertility after experimental testicular torsion and detorsion.

Objective: To evaluate the impact of insulin like growth factor-1(IGF-1) and growth hormone (GH) on testis histology, spermatogenesis, and fertility in prepubertal rats exposed to 6 h of testicular torsion (TT) and detorsion.

Material-method: Forty-eight male Wistar-albino rats weighing 30-70g and at 3-week age were allocated into six groups involving eight rats in each group as follows: Group 1:Sham, Group 2:Control, Group 3:Gelatin, Group 4:Local-IGF-1, 5: Local-GH, Group 6: Systemic-GH. Right testis was only exposed and sutured in the sham group, and right testes were rotated clockwise, 720°, fixed, and 6 h later, detorsion on the testis was done in groups 2-6.

Potential of pectin for biomedical applications: a comprehensive review.

Pectin is a polysaccharide extracted from various plants, such as apples, oranges, lemons, and it possesses some beneficial effects on human health, including being hypoglycemic and hypocholesterolemic. Therefore, pectin is used in various pharmaceutical and biomedical applications. Meanwhile, its low mechanical strength and fast degradation rate limit its usage as drug delivery devices and tissue engineering scaffolds.

pH responsive release of curcumin from photocrosslinked pectin/gelatin hydrogel wound dressings.

The aim of this study was to develop hydrogel wound dressings made of photocrosslinkable pectin and gelatin with pH dependent release of curcumin, an antimicrobial agent. Methacrylated forms of pectin and gelatin (PeMA and GelMA, respectively) were synthesized, and hydrogels were prepared with different compositions (1:1, 1:2 and 1:3 v/v ratios of PeMA and GelMA) by UV exposure. Pure GelMA was used as control group.

Lithocholic acid conjugated mPEG-b-PCL micelles for pH responsive delivery to breast cancer cells.

In this study, micelles composed of methoxy poly(ethylene glycol)-block-poly(ε-caprolactone) copolymer (mPEG-b-PCL), which has ionically conjugated lithocholic acid (LCA) and providing pH sensitive release of LCA in acidic media, were prepared as drug carrier devices for cancer therapy. Micelles were produced by co-solvent evaporation method at two different temperatures (60 °C and 25 °C) and coded as LCA**M and LCA**M, respectively). Hydrodynamic diameters were 86.

Enhancing esophageal repair with bioactive bilayer mesh containing FGF.

We aimed to prepare a bioactive and biodegradable bilayer mesh formed by fibroblast growth factor (FGF) loaded gelatin film layer, and poly ε-caprolactone (PCL) film layer, and to investigate its treatment efficacy on esophageal anastomosis. It is envisaged that the bioactive mesh in in vivo model would improve tissue healing in rats. The full thickness semicircular defects of 0.

3D printed hybrid bone constructs of PCL and dental pulp stem cells loaded GelMA.

Fabrication of scaffolds using polymers and then cell seeding is a routine protocol of tissue engineering applications. Synthetic polymers have adequate mechanical properties to substitute for some bone tissue, but they are generally hydrophobic and have no specific cell recognition sites, which leads to poor cell affinity and adhesion. Some natural polymers, have high cell affinity but are mechanically weak and do not have the strength required as a bone supporting material.

Bioinks-materials used in printing cells in designed 3D forms.

Use of materials to activate non-functional or damaged organs and tissues goes back to early ages. The first materials used for this purpose were metals, and in time, novel materials such as ceramics, polymers and composites were introduced to the field to serve in medical applications. In the last decade, the advances in material sciences, cell biology, technology and engineering made 3D printing of living tissues or organ models in the designed structure and geometry possible by using cells alone or together with hydrogels through additive manufacturing.

A two-compartment bone tumor model to investigate interactions between healthy and tumor cells.

We produced a novel three-dimensional (3D) bone tumor model (BTM) to study the interactions between healthy and tumor cells in a tumor microenvironment, the migration tendency of the tumor cells, and the efficacy of an anticancer drug, Doxorubicin, on the cancer cells. The model consisted of two compartments: (a) a healthy bone tissue mimic, made of poly(lactic acid-co-glycolic acid) (PLGA)/beta-tricalcium phosphate (β-TCP) sponge seeded with human fetal osteoblastic cells (hFOB) and human umbilical vein endothelial cells (HUVECs), and (b) a tumor mimic, made of lyophilized collagen sponge seeded with human osteosarcoma cells (Saos-2). The tumor mimic component was placed into a central cavity created in the healthy bone mimic and together they constituted the complete 3D bone tumor model (3D-BTM).

3D and 4D Printing of Polymers for Tissue Engineering Applications.

Three-dimensional (3D) and Four-dimensional (4D) printing emerged as the next generation of fabrication techniques, spanning across various research areas, such as engineering, chemistry, biology, computer science, and materials science. Three-dimensional printing enables the fabrication of complex forms with high precision, through a layer-by-layer addition of different materials. Use of intelligent materials which change shape or color, produce an electrical current, become bioactive, or perform an intended function in response to an external stimulus, paves the way for the production of dynamic 3D structures, which is now called 4D printing.

Anatomical meniscus construct with zone specific biochemical composition and structural organization.

A PCL/hydrogel construct that would mimic the structural organization, biochemistry and anatomy of meniscus was engineered. The compressive (380 ± 40 kPa) and tensile modulus (18.2 ± 0.

Biomechanical analysis of a modified suture technique for septal extension grafts: Transloop suture.

Background: A successful rhinoplasty procedure requires a well-defined and properly projected nasal tip; however, surgical control of the nasal tip is difficult. The aim of this investigation was to assess the efficacy and safety of a modified suture technique, which can be used to fix the caudal septal extension graft during primary rhinoplasty of the Asian population and revision septorhinoplasties of the Caucasian population, and to compare it with those of other commonly used techniques.

Methods: After peeling of perichondrium of scapular cartilages, cartilage pieces of 3 × 1 cm in size and 2 mm in thickness were divided into two from the midline.

An estradiol releasing, proangiogenic hydrogel as a candidate material for use in soft tissue interposition.

Introduction And Objectives: Soft tissue interposition (STI) using local and/or regional flaps is often necessary in urogenital reconstruction to stimulate wound healing and prevent recurrence. Harvesting STI flaps can cause donor site morbidity and may not be available in some patients. In this study, we designed estradiol (E2) releasing hydrogel that could be used as an alternative to a STI flap and to investigate its ability to stimulate tissue production and angiogenesis.

Square prism micropillars on poly(methyl methacrylate) surfaces modulate the morphology and differentiation of human dental pulp mesenchymal stem cells.

Use of soluble factors is the most common strategy to induce osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro, but it may raise potential side effects in vivo. The topographies of the substrate surfaces affect cell behavior, and this could be a promising approach to guide stem cell differentiation. Micropillars have been reported to modulate cellular and subcellular shape, and it is particularly interesting to investigate whether these changes in cell morphology can modulate gene expression and lineage commitment without chemical induction.

A 3D printed PCL/hydrogel construct with zone-specific biochemical composition mimicking that of the meniscus.

Engineering the meniscus is challenging due to its bizonal structure; the tissue is cartilaginous at the inner portion and fibrous at the outer portion. Here, we constructed an artificial meniscus mimicking the biochemical organization of the native tissue by 3D printing a meniscus shaped PCL scaffold and then impregnating it with agarose (Ag) and gelatin methacrylate (GelMA) hydrogels in the inner and outer regions, respectively. After incubating the constructs loaded with porcine fibrochondrocytes for 8 weeks, we demonstrated that presence of Ag enhanced glycosaminoglycan (GAG) production by about 4 fold (p < 0.

Preparation and characterization of poly(ε-caprolactone) scaffolds modified with cell-loaded fibrin gel.

Poly(ε-caprolactone) (PCL) is one of the most commonly used polymers in the production of tissue engineered scaffolds for hard tissue treatments. Incorporation of cells into these scaffolds significantly enhances the healing rate of the tissue. In this study, PCL scaffolds were prepared by wet spinning technique and modified by addition of fibrinogen in order to form a fibrin network between the PCL fibers.

Cell behavior on the alginate-coated PLLA/PLGA scaffolds.

Here, we investigated the effect of preparation temperature and alginate-coating on L929 fibroblast behavior on lyophilized microporous PLLA/PLGA (95:5, w/w) scaffolds. The lower freezing temperature used during lyophilization (-80 °C) resulted in smaller pores (around 50 μm) and higher compressive modulus (1500 kPa) than those prepared at the higher temperature (-20 °C) (pore size: 120 μm, compressive modulus: 600 kPa) (p < 0.01).

Hydrogels of agarose, and methacrylated gelatin and hyaluronic acid are more supportive for in vitro meniscus regeneration than three dimensional printed polycaprolactone scaffolds.

In this study, porcine fibrochondrocyte-seeded agarose, methacrylated gelatin (GelMA), methacrylated hyaluronic acid (MeHA) and GelMA-MeHA blend hydrogels, and 3D printed PCL scaffolds were tested under dynamic compression for potential meniscal regeneration in vitro. Cell-carrying hydrogels produced higher levels of extracellular matrix (ECM) components after a 35-day incubation than the 3D printed PCL. Cells on GelMA exhibited strong cell adhesion (evidenced with intense paxillin staining) and dendritic cell morphology, and produced an order of magnitude higher level of collagen (p < 0.

A bilayer scaffold prepared from collagen and carboxymethyl cellulose for skin tissue engineering applications.

Treatment of chronic skin wound such as diabetic ulcers, burns, pressure wounds are challenging problems in the medical area. The aim of this study was to design a bilayer skin equivalent mimicking the natural one to be used as a tissue engineered skin graft for use in the treatments of problematic wounds, and also as a model to be used in research related to skin, such as determination of the efficacy of transdermal bioactive agents on skin cells and treatment of acute skin damages that require immediate response. In this study, the top two layers of the skin were mimicked by producing a multilayer construct combining two different porous polymeric scaffolds: as the dermis layer a sodium carboxymethyl cellulose (NaCMC) hydrogel on which fibroblasts were added, and as the epidermis layer collagen (Coll) or chondroitin sulfate-incorporated collagen (CollCS) on which keratinocytes were added.

Square prism micropillars improve osteogenicity of poly(methyl methacrylate) surfaces.

Osteogenicity and osteointegration of materials is one of the key elements of the success of bone implants. Poly(methyl methacrylate) (PMMA) is the basic compound of bone cement and has been widely investigated for other orthopedic applications, but its poor osteointegration and the subsequent loosening of implant material limits its widespread use as bone implants. Micropillar features on substrate surfaces were recently reported to modulate cell behavior through alteration of cell morphology and promotion of osteogenesis.

Effects of microarchitecture and mechanical properties of 3D microporous PLLA-PLGA scaffolds on fibrochondrocyte and L929 fibroblast behavior.

There are several reports studying cell behavior on surfaces in 2D or in hydrogels in 3D. However, cell behavior in 3D microporous scaffolds has not been investigated extensively. In this study, poly(L-lactic acid)/poly(lactic acid-co-glycolic acid) (PLLA/PLGA)-based microporous scaffolds were used to study the effects of scaffold microarchitecture and mechanical properties on the behavior of two different cell types, human meniscal fibrochondrocytes and L929 mouse fibroblasts.

Nuclear targeting peptide-modified, DOX-loaded, PHBV nanoparticles enhance drug efficacy by targeting to Saos-2 cell nuclear membranes.

The aim of this study was to target nano sized (266 ± 25 nm diameter) poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) particles carrying Doxorubicin (DOX), an anticancer agent, to human osteosarcoma cells (Saos-2). A nuclear targeting molecule (Nuclear Localization Signal, NLS), a 17 a.a.