Biodegradation and bioresorption of poly(ɛ-caprolactone) nanocomposite scaffolds

Biocompatible Poly(ε-Caprolactone) Nanocapsules Enhance the Bioavailability, Antibacterial, and Immunomodulatory Activities of Curcumin

Curcumin (Cur), the primary curcuminoid found in Curcuma longa L., has garnered significant attention for its potential anti-inflammatory and antibacterial properties. However, its hydrophobic nature significantly limits its bioavailability. Additionally, adipose-derived stem cells (ADSCs) possess immunomodulatory properties, making them useful for treating inflammatory and autoimmune conditions. This study aims to verify the efficacy of poly(ε-caprolactone) nanocapsules (NCs) in improving Cur's bioavailability, antibacterial, and immunomodulatory activities. The Cur-loaded nanocapsules (Cur-NCs) were characterized for their physicochemical properties (particle size, polydispersity index, Zeta potential, and encapsulation efficiency) and stability over time. A digestion test simulated the behavior of Cur-NCs in the gastrointestinal tract. Micellar phase analyses evaluated the Cur-NCs' bioaccessibility. The antibacterial activity of free Cur, NCs, and Cur-NCs against various Gram-positive and Gram-negative strains was determined using the microdilution method. ADSC viability, treated with Cur-NCs and Cur-NCs in the presence or absence of lipopolysaccharide, was analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay. Additionally, ADSC survival was assessed through the Muse apoptotic assay. The expression of both pro-inflammatory (interleukin-1β and tumor necrosis factor-α) and anti-inflammatory (IL-10 and transforming growth factor-β) cytokines on ADSCs was evaluated by real-time polymerase chain reaction. The results demonstrated high stability post-gastric digestion of Cur-NCs and elevated bioaccessibility of Cur post-intestinal digestion. Moreover, Cur-NCs exhibited antibacterial activity against Escherichia coli without affecting Lactobacillus growth. No significant changes in the viability and survival of ADSCs were observed under the experimental conditions. Finally, Cur-NCs modulated the expression of both pro- and anti-inflammatory cytokines in ADSCs exposed to inflammatory stimuli. Collectively, these findings highlight the potential of Cur-NCs to enhance Cur's bioavailability and therapeutic efficacy, particularly in cell-based treatments for inflammatory diseases and intestinal dysbiosis.

Evaluation of the effects of decellularized extracellular matrix nanoparticles incorporation on the polyhydroxybutyrate/nano chitosan electrospun scaffold for cartilage tissue engineering

Recent research focuses on fabricating scaffolds imitating the extracellular matrix (ECM) in texture, composition, and functionality. Moreover, specific nano-bio-particles can enhance cell differentiation. Decellularized ECM nanoparticles possess all of the mentioned properties. In this research, cartilage ECM, extracted from the cow's femur condyle, was decellularized, and ECM nanoparticles were synthesized. Finally, nanocomposite electrospun fibers containing polyhydroxybutyrate (PHB), chitosan (Cs) nanoparticles, and ECM nanoparticles were fabricated and characterized. TEM and DLS results revealed ECM nanoparticle sizes of 17.51 and 21.6 nm, respectively. Optimal performance was observed in the scaffold with 0.75 wt% ECM nanoparticles (PHB-Cs/0.75E). By adding 0.75 wt% ECM, the ultimate tensile strength and elongation at break increased by about 29 % and 21 %, respectively, while the water contact angle and crystallinity decreased by about 36° and 2 %, respectively. Uneven and rougher surfaces of the PHB-Cs/0.75E were determined by FESEM and AFM images, respectively. TEM images verified the uniform dispersion of nanoparticles within the fibers. After 70 days of degradation in PBS, the PHB-Cs/0.75E and PHB-Cs scaffolds demonstrated insignificant weight loss differences. Eventually, enhanced viability, attachment, and proliferation of the human costal chondrocytes on the PHB-Cs/0.75E scaffold, concluded from MTT, SEM, and DAPI staining, confirmed its potential for cartilage tissue engineering.

Evaluation of the effects of halloysite nanotube on polyhydroxybutyrate - chitosan electrospun scaffolds for cartilage tissue engineering applications

Scaffolding method and material that mimic the extracellular matrix (ECM) of host tissue is an integral part of cartilage tissue engineering. This study aims to enhance the properties of electrospun scaffolds made of polyhydroxybutyrate (PHB) - Chitosan (Cs) by adding 1, 3, and 5 wt% halloysite nanotubes (HNT). The morphological, mechanical, and hydrophilicity evaluations expressed that the scaffold containing 3 wt% HNT exhibits the most appropriate features. The FTIR and Raman analysis confirmed hydrogen bond formation between the HNT and PHB-Cs blend. 3 wt% of HNT incorporation decreased the mean fibers' diameter from 965.189 to 745.16 nm and enhanced tensile strength by 169.4 %. By the addition of 3 wt% HNT, surface contact angle decreased from 61.45° ± 3.3 to 46.65 ± 1.8° and surface roughness increased from 684.69 to 747.62 nm. Our findings indicated that biodegradation had been slowed by incorporating HNT into the PHB-Cs matrix. Also, MTT test results demonstrated a significant increase in cell viability of chondrocytes on the PHB-Cs/3 wt% HNT (PC-3H) scaffold after 7 days of cell culture. Accordingly, the PC-3H scaffold can be considered a potential candidate for cartilage tissue engineering.

Wastewater Treatment and Biomedical Applications of Montmorillonite Based Nanocomposites: A Review

Background::

Rapid industrialisation, population growth and technological race worldwide have brought adverse consequences on water resources and as a result affect human health. Toxic metal ions, non-biodegradable dyes, organic pollutants, pesticides, pharmaceuticals are among the chief hazardous materials released into the water bodies from various sources. These hazardous contaminants drastically affect the flora and fauna globally leading to health deterioration there by giving rise to new biomedical challenges.

Hypothesis::

Montmorillonite based nanocomposites (MMTCs) have drawn an attention of the researchers to design environmental friendly, advanced and hygienic nanocomposites for wastewater treatment and biomedical purposes. Montmorillonite clay possesses peculiar physical and chemical properties that include enhanced surface reactivity, improved rheological performance, exorbitant miscibility in water due to which it shows highly favourable interactions with polymers, drugs, metals, mixed metals and metal oxides leading to the fabrication of different types of advanced montmorillonite based nanocomposites that have remarkable applications

Methodology::

Here we review the structural characteristics of montmorillonite clay, advances in the synthetic techniques involved in the fabrication of montmorillonite nanocomposites, their applications in waste water treatment and in bio medical field. The recently developed montmorillonite nanocomposites for (1) waste water treatment as nano-adsorbents for the elimination of toxic inorganic species such as metal ions and heterogeneous photo-catalysts for photo degradation of dyes, pesticides and pharmaceuticals (2) biomedical utilization viz drug delivery, wound amelioration, bone cement, tissue engineering etc. are presented

Conclusion::

The review exclusively focuses on recent research on montmorillonite based nanocomposites and their application in wastewater treatment and in biomedical field

Low-temperature extrusion-based 3D printing of icariin-laden scaffolds for osteogenesis enrichment

Despite the accessibility to porous architectures through various biofabrication approaches for tissue engineering, incorporating various active growth regulators within their matrices that act as biochemical cues is also an essential attribute for effective tissue growth. To address these facts, icariin (ICA)-encapsulated polymeric scaffolds are fabricated using a low-temperature extrusion-based three-dimensional (3D) printing technology for efficiently promoting osteogenesis. This approach not only resulted in the generation of porous architectures but also substantially maintained the bio-efficacy of the encapsulated ICA. Moreover, these composite scaffolds based on poly(ε-caprolactone) (PCL) and tricalcium phosphate (β-TCP) encapsulated with ICA (ITP scaffolds) are systematically characterized using various techniques before and after printing. Furthermore, various investigations relevant to biodegradability, biocompatibility, ICA release, and osteogenic ability of the ITP scaffolds are explored. The intact physiochemical properties of the materials, sustained release of ICA from the scaffolds, and high biosafety at various levels ranging from cellular to animal efficiently promoted the proliferation of mouse bone marrow mesenchymal stem cells (BMSCs) and their differentiation to osteoblasts. Together, the utilization of low-temperature extrusion approach provides a convenient and eco-friendly means of fabricating highly porous 3D architectures that supply the required growth regulators in their active form for tissue regeneration.

Chemistry, Structures, and Advanced Applications of Nanocomposites from Biorenewable Resources

Researchers have recently focused on the advancement of new materials from biorenewable and sustainable sources because of great concerns about the environment, waste accumulation and destruction, and the inevitable depletion of fossil resources. Biorenewable materials have been extensively used as a matrix or reinforcement in many applications. In the development of innovative methods and materials, composites offer important advantages because of their excellent properties such as ease of fabrication, higher mechanical properties, high thermal stability, and many more. Especially, nanocomposites (obtained by using biorenewable sources) have significant advantages when compared to conventional composites. Nanocomposites have been utilized in many applications including food, biomedical, electroanalysis, energy storage, wastewater treatment, automotive, etc. This comprehensive review provides chemistry, structures, advanced applications, and recent developments about nanocomposites obtained from biorenewable sources.

3D printed porous PLA/nHA composite scaffolds with enhanced osteogenesis and osteoconductivity in vivo for bone regeneration

Repair and regeneration of large bone defects is still a challenge, especially for defects which are the irregular and complex. Three-dimension (3D) printing, as an advanced fabrication technology, has been received considerable attentions due to its high precision, customized geometry and personalization. In this study, 3D porous polylactic acid/nano hydroxyapatite (PLA/nHA) composite scaffolds with enhanced osteogenesis and osteoconductivity were successfully fabricated by desktop fused deposition modeling technology. Morphological, composition and structural analysis revealed that nHA was successfully introduced into the PLA system and homogeneously dispersed in the printed PLA/nHA scaffolds. In vitro antibacterial experiment confirmed that the printed porous PLA/nHA scaffolds have good ability for loading and releasing vancomycin and levofloxacin. Meanwhile, MG-63 cells were used to evaluate the cytocompatibility of printed porous PLA/nHA scaffolds by proliferation and cellular morphological analysis. In addition, rabbit model was established to evaluate the osteogenesis and osteoconductivity of printed PLA/nHA scaffolds. All these results suggested that the 3D printed PLA/nHA scaffolds have great potential for repairing and regeneration of large bone defects.

Cell-free artificial implants of electrospun fibres in a three-dimensional gelatin matrix support sciatic nerve regeneration in vivo

Surgical repair of larger peripheral nerve lesions requires the use of autologous nerve grafts. At present, clinical alternatives to avoid nerve transplantation consist of empty tubes, which are only suitable for the repair over short distances and have limited success. We developed a cell-free, three-dimensional scaffold for axonal guidance in long-distance nerve repair. Sub-micron scale fibres of biodegradable poly-ε-caprolactone (PCL) and collagen/PCL (c/PCL) blends were incorporated in a gelatin matrix and inserted in collagen tubes. The conduits were tested by replacing 15-mm-long segments of rat sciatic nerves in vivo. Biocompatibility of the implants and nerve regeneration were assessed histologically, with electromyography and with behavioural tests for motor functions. Functional repair was achieved in all animals with autologous transplants, in 12 of 13 rats that received artificial implants with an internal structure and in half of the animals with empty nerve conduits. In rats with implants containing c/PCL fibres, the extent of recovery (compound muscle action potentials, motor functions of the hind limbs) was superior to animals that had received empty implants, but not as good as with autologous nerve transplantation. Schwann cell migration and axonal regeneration were observed in all artificial implants, and muscular atrophy was reduced in comparison with animals that had received no implants. The present design represents a significant step towards cell-free, artificial nerve bridges that can replace autologous nerve transplants in the clinic. Copyright © 2017 John Wiley & Sons, Ltd.