Structure Restoration of Thermally Denatured Collagen by Ultrahigh Pressure Treatment

Tissue-specific gelatin bioink as a rheology modifier for high printability and adjustable tissue properties

Decellularized extracellular matrix (dECM) has emerged as an exceptional biomaterial that effectively recapitulates the native tissue microenvironment for enhanced regenerative potential. Although various dECM bioinks derived from different tissues have shown promising results, challenges persist in achieving high-resolution printing of flexible tissue constructs because of the inherent limitations of dECM's weak mechanical properties and poor printability. Attempts to enhance mechanical rigidity through chemical modifications, photoinitiators, and nanomaterial reinforcement have often compromised the bioactivity of dECM and mismatched the desired mechanical properties of target tissues. In response, this study proposes a novel method involving a tissue-specific rheological modifier, gelatinized dECM. This modifier autonomously enhances bioink modulus pre-printing, ensuring immediate and precise shape formation upon extrusion. The hybrid bioink with GeldECM undergoes a triple crosslinking system-physical entanglement for pre-printing, visible light photocrosslinking during printing for increased efficiency, and thermal crosslinking post-printing during tissue culture. A meticulous gelatinization process preserves the dECM protein components, and optimal hybrid ratios modify the mechanical properties, tailoring them to specific tissues. The application of this sequential multiple crosslinking designs successfully yielded soft yet resilient tissue constructs capable of withstanding vigorous agitation with high shape fidelity. This innovative method, founded on mechanical modulation by GeldECM, holds promise for the fabrication of flexible tissues with high resilience.

Ultrahigh pressure field: A friendly pathway for regulating the cellular adhesion and migration capacity of collagen

Customized control of the biological response between the material matrix and cells is a crucial aspect in the development of the next generation of collagen materials. This study aims to investigate the effects of ultrahigh pressure treatment on the interaction between collagen and cells by subjecting bovine tendon collagen to different intensities of ultrahigh pressure field. The results indicate that ultrahigh pressure treatment alters the spatial folding of collagen, causing distortion of its triple helical conformation and exposing more free amino groups and hydrophobic regions. As a result, collagen's cell adhesion capability and ability to promote cell migration are significantly enhanced. Optimal cell adhesion and migration capabilities are observed in collagen samples treated at 500 MPa for 15 min. However, further increasing the intensity of the ultrahigh pressure treatment leads to severe damage to the triple-helical structure of collagen, along with re-aggregation of free amino groups and hydrophobic moieties, thereby reducing collagen's cell adhesion capability and ability to promote cell migration. Therefore, ultrahigh pressure treatment offers a promising method to effectively regulate collagen-cell adhesion and promote cell migration without the need for external components. This provides a potential means for the customized enhancement of collagen-based material interfaces.

Novel Efficient Physical Technologies for Enhancing Freeze Drying of Fruits and Vegetables: A Review

Drying is the main technical means of fruit and vegetable processing and storage; freeze drying is one of the best dehydration processes for fruit and vegetables, and the quality of the final product obtained is the highest. The process is carried out under vacuum and at low temperatures, which inhibits enzymatic activity and the growth and multiplication of micro-organisms, and better preserves the nutrient content and flavor of the product. Despite its many advantages, freeze drying consumes approximately four to ten times more energy than hot-air drying, and is more costly, so freeze drying can be assisted by means of highly efficient physical fields. This paper reviews the definition, principles and steps of freeze drying, and introduces the application mechanisms of several efficient physical fields such as ultrasonic, microwave, infrared radiation and pulsed electric fields, as well as the application of efficient physical fields in the freeze drying of fruits and vegetables. The application of high efficiency physical fields with freeze drying can improve drying kinetics, increase drying rates and maintain maximum product quality, providing benefits in terms of energy, time and cost. Efficient physical field and freeze drying technologies can be well linked to sustainable deep processing of fruit and vegetables and have a wide range of development prospects.

UC-II® undenatured type II collagen data show retention during functional food and beverage prototype processing

Nowadays, collagen is widely used in food and beverage industries to enhance the nutritional and health value of the products. While many see this as an ideal way to incorporate more collagen into their diets, the exposure of these proteins to high temperature or acidic and alkaline solutions may negatively affect the quality and activity of these supplements. In general, the manufacturing of functional food and beverages often largely depends on the stability of the active ingredients during processing. The high temperatures, humidity, and low pH of processing may reduce product nutrient retention. Hence, understanding stability of collagen is of great significance and these data were gathered to determine the extent of undenatured type II collagen retention under different processing conditions. UC-II® undenatured type II collagen is a patented form of collagen derived from chicken sternum cartilage, and different food and beverage prototypes incorporating UC-II® undenatured type II collagen were produced. The content of undenatured type II collagen was compared in their pre-and post-manufacturing formats using an enzyme-linked immunosorbent assay. The undenatured type II collagen retention varied depending upon the prototype, with the highest amount of undenatured type II collagen retention occurring in nutritional bars (approximately 100%), followed by chews (98%), gummies (96%), and dairy beverages (81%). The present work also showed that recovery of the undenatured type II collagen depends on the exposure time, temperature and pH of the prototype.

Modification of natural pigskin collagen via cryogrinding: a focused study on its physiochemical properties

Natural pigskin was subjected to cryogrinding before extraction, and effects of the approach on extraction rate, structure, and properties of collagen were prospected systematically. It was found that the extraction rate multiplied gradually from 22% to 40% with an extended grinding duration from 0 to 20 min. Compared with natural collagen, the ground one soared by about 80% concerning the net yield. Electrophoresis revealed the stereo structures of the extracted collagen were not destroyed when ground, while a small amount of it degraded accordingly, whose conclusion was further corroborated by circular dichroism (CD) and infrared spectrometry. Results from contact angle (CA) test clarified that the hydrophilicity of collagen enhanced with prolonged grinding. Moreover, analysis of fibrillogenesis behavior verified that, after grinding, the assembly rate for collagen in the turbidity assay dented with a lengthened equilibrium time; finer fibril network with larger pore size and weakened elasticity was later observed. Methyl thiazolyl tetrazolium (MTT) analysis manifested that ground collagen was more conducive to cell proliferation. This polymer processing approach not only provides us with a facile approach to manipulate capacities of collagen but also sheds light on other potential substances beneath the same principle.

Effect of molecular chirality on the collagen self-assembly

The function of molecular chirality in collagen self-assembly was presented.

A quantum dot-based fluorescence sensing platform for the efficient and sensitive monitoring of collagen self-assembly

An efficient and sensitive assay for monitoring collagen self-assembly is presented.