Stabilisation of Recombinant Human Basic Fibroblast Growth Factor (FGF-2) against Stressors Encountered in Medicinal Product Processing and Evaluation

A case of acquired acrodermatitis enteropathica in a 91-year-old man

This report is a care experience of acrodermatitis enteropathica caused by inadequate zinc intake. The male patient is 91 years old, he had been fasting caused by recurrent acute pancreatitis, and intravenous nutrition lacking zinc. The case was based on multidisciplinary treatment, reviewing clinical data, and making a definitive diagnosis. Zinc supplementation is based on monitoring serum zinc levels, and for the skin wound condition to choose timely and effective dressing changes, life care, keep the wound dry, control the exudate seepage, and promote the healing of the patient's wound. With treatment and care, the patient's skin damage was brought under control and the prognosis was favorable.

Functional interleukin-4 releasing microparticles impact THP-1 differentiated macrophage phenotype

Introduction

Macrophage cell therapies offer potential treatment in inflammatory diseases due to their ability to mobilize and stimulate their environment. However, successful treatment requires a pro-regenerative macrophage phenotype to be retained in vivo. Polymeric microparticles may provide a potential route to direct and sustain macrophage phenotype. Interleukin-4 (IL-4) is the most commonly used cytokine for in vitro modulation towards M2a macrophage phenotype. We designed IL-4 encapsulated microparticles to investigate the impact of drug release kinetics and developed a robust human peripheral blood monocyte cell (THP-1) in vitro assay to assess functional IL-4 release upon macrophage phenotype.

Methods

IL-4 was encapsulated with human serum albumin (HSA) in microparticles fabricated from a blend of PLGA and a PLGA-PEG-PLGA triblock copolymer. Functional release of IL-4 and HSA over different time periods was measured using ELISAs. THP-1 differentiated macrophages were cultured either in direct contact with microparticles or indirectly through transwells. The immunomodulatory impact of microparticles on THP-1 cells were measured using ELISA and qPCR.

Results and Discussion

IL-4 release kinetics fit with the first-order release kinetics model, indicating concentration dependent release. IL-4/HSA encapsulated microparticles modulated THP-1 differentiated macrophages towards pro-immunoregulatory subgroups. This strategy provides a novel approach in drug carrier development for in vitro assessments of macrophage phenotype to inform development of targeted therapies for inflammation and immune modulation.

Integration of Zn2+, ATP, and bFGF to Nanodressing with Core-Shell Structure Fabricated by Emulsion Electrospinning for Wound Healing

Basic fibroblast growth factor (bFGF) plays an important role in active wound repair. However, the existing dosage forms in clinical applications are mainly sprays and freeze-dried powders, which are prone to inactivation and cannot achieve a controlled release. In this study, a bioactive wound dressing named bFGF-ATP-Zn/polycaprolactone (PCL) nanodressing with a "core-shell" structure was fabricated by emulsion electrospinning, enabling the sustained release of bFGF. Based on the coordination and electrostatic interactions among bFGF, ATP, and Zn2+, as well as their synergistic effect on promoting wound healing, a bFGF-ATP-Zn ternary combination system was prepared with higher cell proliferation activity and used as the water phase for emulsion electrospinning. The bFGF-ATP-Zn/PCL nanodressing demonstrated improved mechanical properties, sustained release of bFGF, cytocompatibility, and hemocompatibility. It increased the proliferation activity of human dermal fibroblasts (HDFs) and enhanced collagen secretion by 1.39 and 3.45 times, respectively, while reducing the hemolysis rate to 3.13%. The application of the bFGF-ATP-Zn/PCL nanodressing in mouse full-thickness skin defect repair showed its ability to accelerate wound healing and reduce wound scarring within 14 days. These results provide a research basis for the development and application of this bioactive wound dressing product.

A review on the safety of growth factors commonly used in cultivated meat production

Growth factors are commonly added to cell culture media in cellular agriculture to mimic the endogenous process of proliferation and differentiation of cells. Many of these growth factors are endogenous to humans and known to be present in the edible tissues and milk of food animals. However, there is little or no information on the use of growth factors intentionally added in food production before the advent of cultivated meat. Ten commonly used growth factors have been reviewed to include information on their mode of action, bioavailability, occurrence in food and food animals, endogenous levels in humans, as well as exposure and toxicological information drawn from relevant animal studies and human clinical trials with a focus on oral exposure. In addition, a comparison of homology of growth factors was done to compare the sequence homology of growth factors from humans and domestic animal species commonly consumed as food, such as bovine, porcine, and poultry. This information has been gathered as the starting point to determine the safety of use of growth factors in cultivated meat meant for human consumption. The change in levels of growth factors measured in human milk and bovine milk after pasteurization and high-temperature treatment is discussed to give an indication of how commercial food processing can affect the levels of growth factors in food. The concept of substantial equivalence is also discussed together with a conservative exposure estimation. More work on how to integrate in silico assessments into the routine safety assessment of growth factors is needed.

Essential elements for spatiotemporal delivery of growth factors within bio-scaffolds: A comprehensive strategy for enhanced tissue regeneration

The precise delivery of growth factors (GFs) in regenerative medicine is crucial for effective tissue regeneration and wound repair. However, challenges in achieving controlled release, such as limited half-life, potential overdosing risks, and delivery control complexities, currently hinder their clinical implementation. Despite the plethora of studies endeavoring to accomplish effective loading and gradual release of GFs through diverse delivery methods, the nuanced control of spatial and temporal delivery still needs to be elucidated. In response to this pressing clinical imperative, our review predominantly focuses on explaining the prevalent strategies employed for spatiotemporal delivery of GFs over the past five years. This review will systematically summarize critical aspects of spatiotemporal GFs delivery, including judicious bio-scaffold selection, innovative loading techniques, optimization of GFs activity retention, and stimulating responsive release mechanisms. It aims to identify the persisting challenges in spatiotemporal GFs delivery strategies and offer an insightful outlook on their future development. The ultimate objective is to provide an invaluable reference for advancing regenerative medicine and tissue engineering applications.

In Vitro Assessment of Wound-Healing Efficacy of Stabilized Basic Fibroblast Growth Factor (FGF-2) Solutions

Chronic tympanic membrane perforations (TMP) pose a significant clinical challenge, but basic fibroblast growth factor (FGF-2) shows promise for their treatment, despite its instability in aqueous solutions which hampers the sustained delivery crucial for the healing process. Addressing this, our research focused on the development of stabilized FGF-2 formulations, F5 and F6, incorporating dual, generally regarded as safe (GRAS) excipients to enhance stability and therapeutic efficacy. F5 combined FGF-2 (1600 ng/mL) with 0.05% w/v methylcellulose (MC) and 20 mM alanine, while F6 used FGF-2 with 0.05% w/v MC and 1 mg/mL human serum albumin (HSA). Our findings demonstrate that these novel formulations not only significantly improve the cytoproliferation of human dermal fibroblasts but also exhibit the most potent chemoattractant effects, leading to the highest fibroblast monolayer closure rates (92.5% for F5 and 94.1% for F6 within 24 h) compared to other FGF-2 solutions tested. The comparable performance of F5 and F6 underscores their potential as innovative, less invasive, and cost-effective options for developing otic medicinal products aimed at the effective treatment of chronic TMP.

Compatibility Study of Peptide and Glycerol Using Chromatographic and Spectroscopic Techniques: Application to a Novel Antimicrobial Peptide Cbf-14 Gel

The interactions between active pharmaceutical ingredients (APIs) and excipients may lead to API degradation, thereby affecting the safety and efficacy of drug products. Cbf-14 is a synthetic peptide derived from Cathelicidin-BF, showing potential for bacterial and fungal infections. In order to assess impurities in Cbf-14 gel, we developed a two-dimensional liquid chromatography coupled with quadrupole/time-of-flight mass spectrometric method. A total of eleven peptide degradation impurities were identified and characterized. Furthermore, the compatibility tests were conducted to evaluate the interactions of Cbf-14 with glycerol and methylcellulose, respectively. The results revealed that the impurities originated from condensation reactions between Cbf-14 and aldehydes caused by glycerol degradation. Several aldehydes were employed to validate this hypothesis. The formation mechanisms were elucidated as Maillard reactions between primary amino groups of Cbf-14 and aldehydes derived from glycerol degradation. Additionally, the compatibility of Cbf-14 with glycerol from different sources and with varying storage times was investigated. Notably, the interaction products in the gel increased with extended storage time, even when fresh glycerol for injection was added. This study offers unique insights into the compatibility study of peptides and glycerol, contributing to the ongoing quality study of Cbf-14 gel. It also serves as a reference for the design of other peptide preparations and excipients selections.

A simple and robust serum-free media for the proliferation of muscle cells

Cultivated meat production requires an efficient, robust and highly optimized serum-free cell culture media for the needed upscaling of muscle cell expansion. Existing formulations of serum-free media are complex, expensive and have not been optimized for muscle cells. Thus, we undertook this work to develop a simple and robust serum-free media for the proliferation of bovine satellite cells (SCs) through Design of Experiment (DOE) and Response Surface Methodology (RSM) using precise and high-throughput image-based cytometry. Proliferative attributes were investigated with transcriptomics and long-term performance was validated using multiple live assays. Here we formulated a media based on three highly optimized components; FGF2 (2 ng/mL), fetuin (600 µg/mL) and BSA (75 µg/mL) which together with an insulin-transferrin-selenium (1x) supplement, sustained the proliferation of bovine SCs, porcine SCs and murine C2C12 muscle cells. Remarkably, cells cultured in our media named Tri-basal 2.0+ performed better than cell cultured in 10% FBS, with respect to proliferation. Hence, the optimized Tri-basal 2.0+ enhanced serum-free cell attachment and long-term proliferation, providing an alternative solution to the use of FBS in the production of cultivated meat.

Efficient expression of a cytokine combination in Saccharomyces cerevisiae for cultured meat production

Cultured meat technology is a novel and promising alternative strategy for meat production, and it provides an efficient, safe, and sustainable way to supply animal protein. Cytokines play an important role in promoting the rapid proliferation of cells, but the high cost and potential food safety concerns of commercial cytokines have hindered their application in large-scale cultured meat production. Herein, Saccharomyces cerevisiae C800 was used as a starting strain in which four cytokines were exogenously expressed simultaneously using the Cre-loxP system, including long-chain human insulin growth factor-1, platelet-derived growth factor-BB, basic fibroblast growth factor, and epidermal growth factor. Through promoter optimization, endogenous protease knockout, genomic co-expression, expression frame gene order optimization, and fermentation optimization, a recombinant strain CPK2B2 co-expressing four cytokines was obtained with a yield of 18.35 mg/L. After cell lysis and filter sterilization, the CPK2B2 lysate was directly added to the culture medium of porcine muscle satellite cells (MuSCs). CPK2B2 lysate promoted the growth of MuSCs and increased the proportion of G2/S cells and EdU⁺ cells significantly, indicating its efficacy in promoting cell proliferation. This study provides a simple and cost-saving strategy by using S. cerevisiae to produce a recombinant cytokine combination for cultured meat production.

Cyclic and dimeric fibroblast growth factor 2 variants with high biomedical potential

Fibroblast growth factor 2 (FGF2) is a pleiotropic protein engaged in the regulation of key cellular processes in a wide spectrum of cells. FGF2 is an important object of basic research as well as a molecule used in regenerative medicine, in vitro cell culture maintenance, and as an anticancer drug carrier. However, the unsatisfactory stability and pleiotropic activities of the wild-type FGF2 largely limit its use as a medical product. To overcome these limitations, we have designed a set of FGF2-based macromolecules via sortase A-mediated cyclization and oligomerization. We obtained heparin-switchable FGF2 variants with enhanced stability and improved ability to stimulate cell proliferation and migration. We have shown that stimulation of glucose uptake by adipocytes is modulated by the architecture of FGF2 oligomers. Moreover, we used hyper-stable FGF2 variants for the construction of highly effective drug carriers for selective killing of FGFR1-overproducing cancer cells. The strategy for FGF2 engineering presented in this work provides novel insights into the design of growth factor variants for regenerative and anti-cancer precise medicine.

Anti-fibrotic effects of pharmacologic FGF-2: a review of recent literature

Fibrosis is a process of pathological tissue repair that replaces damaged, formerly functional tissue with a non-functional, collagen-rich scar. Complications of fibrotic pathologies, which can arise in numerous organs and from numerous conditions, result in nearly half of deaths in the developed world. Despite this, therapies that target fibrosis at its mechanistic roots are still notably lacking. The ubiquity of the occurrence of fibrosis in myriad organs emphasizes the fact that there are shared mechanisms underlying fibrotic conditions, which may serve as common therapeutic targets for multiple fibrotic diseases of varied organs. Thus, study of the basic science of fibrosis and of anti-fibrotic modalities is critical to therapeutic development and may have potential to translate across organs and disease states. Fibroblast growth factor 2 (FGF-2) is a broadly studied member of the fibroblast growth factors, a family of multipotent cytokines implicated in diverse cellular and tissue processes, which has previously been recognized for its anti-fibrotic potential. However, the mechanisms underlying this potential are not fully understood, nor is the potential for its use to ameliorate fibrosis in diverse pathologies and tissues. Presented here is a review of recent literature that sheds further light on these questions, with the hopes of inspiring further research into the mechanisms underlying the anti-fibrotic activities of FGF-2, as well as the disease conditions for which pharmacologic FGF-2 might be a useful option in the future.