A large body of experimental evidence suggests that neuroinflammation is a key pathological event triggering and perpetuating the neurodegenerative process associated with many neurological diseases. Therefore, different stimuli, such as lipopolysaccharide (LPS), are used to model neuroinflammation associated with neurodegeneration. By acting at its receptors, LPS activates various intracellular molecules, which alter the expression of a plethora of inflammatory mediators. These factors, in turn, initiate or contribute to the development of neurodegenerative processes. Therefore, LPS is an important tool for the study of neuroinflammation associated with neurodegenerative diseases. However, the serotype, route of administration, and number of injections of this toxin induce varied pathological responses. Thus, here, we review the use of LPS in various models of neurodegeneration as well as discuss the neuroinflammatory mechanisms induced by this toxin that could underpin the pathological events linked to the neurodegenerative process.

https://www.mdpi.com/1422-0067/20/9/2293/pdf

Lipopolysaccharide-Induced Neuroinflammation as a Bridge to Understand Neurodegeneration.

The Blood-Brain Barrier (BBB), a unique structure in the central nervous system (CNS), protects the brain from bloodborne pathogens by its excellent barrier properties. Nevertheless, this barrier limits therapeutic efficacy and becomes one of the biggest challenges in new drug development for neurodegenerative disease and brain cancer. Recent breakthroughs in nanotechnology have resulted in various nanoparticles (NPs) as drug carriers to cross the BBB by different methods. This review presents the current understanding of advanced NP-mediated non-invasive drug delivery for the treatment of neurological disorders. Herein, the complex compositions and special characteristics of BBB are elucidated exhaustively. Moreover, versatile drug nanocarriers with their recent applications and their pathways on different drug delivery strategies to overcome the formidable BBB obstacle are briefly discussed. In terms of significance, this paper provides a general understanding of how various properties of nanoparticles aid in drug delivery through BBB and usher the development of novel nanotechnology-based nanomaterials for cerebral disease therapies.

Overcoming blood–brain barrier transport: Advances in nanoparticle-based drug delivery strategies

Alzheimer’s disease (AD) is the most prevalent form of dementia. Despite decades of research following several theoretical and clinical lines, all existing treatments for the disorder are purely symptomatic. AD research has traditionally been focused on neuronal and glial dysfunction. Although there is a wealth of evidence pointing to a significant vascular component in the disease, this angle has been relatively poorly explored. In this review, we consider the various aspects of vascular dysfunction in AD, which has a significant impact on brain metabolism and homeostasis and the clearance of β-amyloid and other toxic metabolites. This may potentially precede the onset of the hallmark pathophysiological and cognitive symptoms of the disease. Pathological changes in vessel haemodynamics, angiogenesis, vascular cell function, vascular coverage, blood-brain barrier permeability and immune cell migration may be related to amyloid toxicity, oxidative stress and apolipoprotein E (APOE) genotype. These vascular deficits may in turn contribute to parenchymal amyloid deposition, neurotoxicity, glial activation and metabolic dysfunction in multiple cell types. A vicious feedback cycle ensues, with progressively worsening neuronal and vascular pathology through the course of the disease. Thus, a better appreciation for the importance of vascular dysfunction in AD may open new avenues for research and therapy.

https://www.mdpi.com/2077-0383/8/5/651/pdf

Vascular Dysfunction in Alzheimer's Disease: A Prelude to the Pathological Process or a Consequence of It?

Compared with non-degradable materials, biodegradable biomaterials play an increasingly important role in the repairing of severe bone defects, and have attracted extensive attention from researchers. In the treatment of bone defects, scaffolds made of biodegradable materials can provide a crawling bridge for new bone tissue in the gap and a platform for cells and growth factors to play a physiological role, which will eventually be degraded and absorbed in the body and be replaced by the new bone tissue. Traditional biodegradable materials include polymers, ceramics and metals, which have been used in bone defect repairing for many years. Although these materials have more or fewer shortcomings, they are still the cornerstone of our development of a new generation of degradable materials. With the rapid development of modern science and technology, in the twenty-first century, more and more kinds of new biodegradable materials emerge in endlessly, such as new intelligent micro-nano materials and cell-based products. At the same time, there are many new fabrication technologies of improving biodegradable materials, such as modular fabrication, 3D and 4D printing, interface reinforcement and nanotechnology. This review will introduce various kinds of biodegradable materials commonly used in bone defect repairing, especially the newly emerging materials and their fabrication technology in recent years, and look forward to the future research direction, hoping to provide researchers in the field with some inspiration and reference.

/pdf/biodegradable-materials-for-bone-defect-repair-1ngvaf6ux0.pdf

Biodegradable materials for bone defect repair

Evolution of metallic cardiovascular stent materials: A comparative study among stainless steel, magnesium and zinc.

Bioactive glass coatings on metallic implants for biomedical applications.

Alzheimer’s disease, a type of dementia, affects memory, behavior, and cognitive processes in affected individuals. It is one of the prominent diseases, accounting for 60–80% of dementia cases and affecting a significant population of persons over the age of 65 years. While rare, Alzheimer’s disease (AD) may affect the younger population as well. With such a widespread number of persons affected with AD, scientists have undertaken the initiative to develop a cure for this devastating disease; however, it has been deemed quite challenging. A dysfunctional blood-brain barrier, with impaired ability to clear amyloid-β from the brain, has been directly linked to the development of Alzheimer’s disease. The blood-brain barrier restricts the flow of many substances into and out of the brain and serves as a selective and protective barrier to the brain. A proper functioning blood-brain barrier contributes to the maintenance and integrity of the brain. In turn, different systems and mechanisms within the blood-brain barrier are set in place to facilitate mediated passage of materials and substances between the brain and the bloodstream. In relation to AD, the mediation of amyloid-β clearance is of great importance in maintaining the blood-brain barrier’s integrity.

Blood-Brain Barrier Integrity and Clearance of Amyloid-β from the BBB

Bioactive glasses currently play a rather small role in orthopedic procedures when compared to metallic implants, despite its superior bioactivity within the body. Common metallic materials that are used to engineer and manufacture orthopedic implants generally consist of titanium and its alloys, cobalt-chromium alloys, and stainless steel 316L as they provide the best material properties based on their applications. However, these implants tend to carry the following risks: infection, surrounding tissue damage, and improper healing. Typically, it is not the implant that is directly responsible for the tissue damage or rejection, but the interaction between the bodily tissue and the implant. In some cases, when in contact with the physiological environment, a fibrous capsule of scar tissue has been known to form around the grafted implant, therefore interfering with the integration of the implant with the surrounding tissue. Bioactive glass presents as an alternative material that can be considered for surgical orthopedic applications. One major limitation that has prevented bioactive glasses dominance in the orthopedic surgical realm is its lack of ductility, strength, and ability to withstand load-bearing applications in supporting larger bones. This book chapter intends to showcase how bioactive glass is currently used in tissue engineering and its ability to improve and change current commonly used orthopedic implants.

Joy-anne N. Oliver

Papers

Bioactive glass coatings on metallic implants for biomedical applications.

Blood-Brain Barrier Integrity and Clearance of Amyloid-β from the BBB

Bioactive Glasses in Orthopedic Applications