Using type III recombinant human collagen to construct a series of highly porous scaffolds for tissue regeneration.

As an alternative biopolymer material without the risks of the use of animal-derived collagens in soft tissue engineering applications, recombinant human collagen polypeptide (RHC) was used to construct three-dimensional porous scaffolds. RHC and RHC-chitosan (RHC-CHI) porous scaffolds were fabricated using a freeze-drying method to create highly porous internal structures and then cross-linked with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC). All scaffolds had interconnected porous structures with high porosity (90%), and pore size that ranged from 111 µm to 159 µm. The swelling ability and in vitro degradation of the prepared scaffolds were investigated. The mechanical properties could be tailored to meet the requirements of end-use application by adjusting the concentrations of the polymer or cross-linking agent, and the resulting mechanical strengths were comparable to those of biological soft tissues. The cytocompatibility of the fabricated porous scaffolds was investigated by seeding 3T3 fibroblasts into the porous structures, and then cell proliferation, distribution, morphology, and synthesis of extra cellular matrix-associated proteins were assessed. The results indicated that RHC-based porous scaffolds were non-cytotoxic and promoted the attachment and proliferation of the seeded cells. Finally, the in vivo study proved these porous scaffolds were able to accelerate the cell infiltration and collagen deposition that promoted the wound closure. Overall, the results indicate that RHC-based porous scaffolds show promise for use in soft tissue engineering due to their excellent in vitro cytocompatibility and adjustable mechanical properties.

Organic Solar Cells Parameters Extraction and Characterization Techniques.

Organic photovoltaic research is continuing in order to improve the efficiency and stability of the products. Organic devices have recently demonstrated excellent efficiency, bringing them closer to the market. Understanding the relationship between the microscopic parameters of the device and the conditions under which it is prepared and operated is essential for improving performance at the device level. This review paper emphasizes the importance of the parameter extraction stage for organic solar cell investigations by offering various device models and extraction methodologies. In order to link qualitative experimental measurements to quantitative microscopic device parameters with a minimum number of experimental setups, parameter extraction is a valuable step. The number of experimental setups directly impacts the pace and cost of development. Several experimental and material processing procedures, including the use of additives, annealing, and polymer chain engineering, are discussed in terms of their impact on the parameters of organic solar cells. Various analytical, numerical, hybrid, and optimization methods were introduced for parameter extraction based on single, multiple diodes and drift-diffusion models. Their validity for organic devices was tested by extracting the parameters of some available devices from the literature.

A cost-effective, analytical method for measuring metabolic load of mitochondria.

Analysis of cellular energetics is central to understanding metabolic diseases including diabetes and cancer. The two most commonly used methods to monitor cellular respiration are the Seahorse-XF system, and Glo™ assays, which are considered "gold standards". These commercial methods measure energetics indirectly and require considerable financial investment. Here we describe an alternative assay that enables accurate quantification of NADH turnover and that is affordable. This method measures resazurin reduction to resorufin at rising concentrations in the presence of purified mitochondrial extracts until NADH becomes a rate-limiting factor. This indicates the maximal level of NADH turnover in each sample and therefore infers metabolic activity. Here we compare MRC5, MCF7 and MDA231 cell lines which have differing metabolic profiles.

The use of decellularised animal tissue to study disseminating cancer cells.

Since the establishment of cell culture, common practice has been to grow adherent cells in 2D monolayers. Although cells behave completely differently when grown under these artificial conditions, the ease of 2D culturing has meant that this practice still prevails, and adopting conditions that more closely reflect the natural microenvironment has been met with substantial inertia. The alternative, animal models that mimic natural human physiology, are less accessible, strictly regulated and require licences and expensive facilities. Although transition from 2D to 3D cell culturing is gathering momentum, there is a clear need for alternative culturing methods that more closely resemble in vivo conditions. Here, we show that decellularised organs gleaned from discarded animal carcasses are ideal biomimetic scaffolds to support secondary tumour initiation in vitro Further, we describe how to decellularise tissue and perform basic histochemistry and immunofluorescence procedures for cell and matrix detection. Cancer cell behaviour on this matrix is followed by way of an example. Because integration into the traditional work flow is easy and inexpensive, we hope this article will encourage other researchers to adopt this approach.