Progress in biomedical engineering (Bristol, England)最新文献

Peripheral nerve injury (PNI) presents a major neurological challenge, with symptoms varying depending on the extent of axonal damage. Although we have some understanding of pathophysiology and regeneration mechanisms of PNI, achieving complete and accurate functional restoration remains elusive. Current regenerative treatments are often slow, and full recovery is still largely aspirational despite various therapeutic approaches. This review evaluates the advantages and limitations of new bioadhesives and electrical stimulation (ES) therapies, whether used alone or in combination, for promoting healing of PNI. Despite significant progress in nerve repair and regenerationin vitro, clinical validation of these methods is limited, and further research is needed. The strong preclinical evidence supporting the effectiveness of ES and bioadhesives in treating PNI now calls for advancement beyond experimental models to clinical testing.

Peripheral nerve injury (PNI) is a common problem worldwide. PNI can lead to loss of sensory and motor functions, chronic neuropathic pain, and mental health issues, significantly impacting the patients' quality of life. Recent studies revealed that, beyond the topical injury site at peripheral nerves, PNIs can also induce dysfunctions in the central nervous system by causing maladaptive plasticity, which will result in exaggeration and exacerbation of the pathological condition caused by the primary injuries. The typical therapy strategies for traumatic PNI treatment are using sutures, nerve autografts, or conduits in cases requiring surgical intervention as well as applying physical-based rehabilitation to facilitate functional recovery. However, the functional restoration is generally unsatisfactory due to insufficient regeneration and long-lasting maladaptive neuroplasticity in the nervous system. In this review, we summarized various neurotrophic factors and neuroprotective agents that have been extensively studied as adjuvant therapies to enhance recovery efficiency after PNIs in the last two decades. Particularly, with the rapid development of biomaterials and bioengineering, controllable drug delivery techniques have shown great potential to maintain the drug bioactivity and, consequently, prolonging the therapeutic effects. Additionally, we explored the virus-based gene delivery technique, which has been used to transduce neural cells for enhancing nerve regeneration. Finally, we discussed current challenges, including inadequate motor function restoration, poorly defined rehabilitation protocols, unresolved chronic inflammation, and limited understanding of macrophage dynamics. We also offered perspectives on integrating various approaches to develop effective and comprehensive treatment strategies for PNIs.

Melt electrowriting (MEW) is an advanced additive manufacturing technique that offers unprecedented microscale control over polymer fiber deposition for tissue engineering applications. This review focuses on recent advancements in MEW technology beyond flat collectors to non-planar, anatomically relevant structures. Such non-planar MEW is enabled by maintaining stable electric field control through a consistent nozzle-to-collector distance, using custom 3D-printed insulating collectors, and multi-axis MEW setup. These advancements allow accurate fiber patterning on curved surfaces and make non-planar MEW feasible for complex scaffold geometries. In parallel, the integration of MEW with complementary fabrication methods (such as fused deposition modeling, electrospinning, and bioprinting) has emerged, permitting the fabrication of intricate, multi-functional scaffolds that closely mimic natural tissue architectures. Automated, multi-parameter process control strategies, through real-time feedback systems incorporating machine vision and artificial intelligence, further improve fiber deposition accuracy and scaffold reproducibility. This review highlights both the key breakthroughs and remaining challenges in non-planar MEW, underscoring the technology's transformative potential in tissue engineering to create highly customized, biomimetic, and physiologically relevant tissue structures.

Stroke, a vascular disorder affecting the nervous system, is the third-leading cause of death and disability combined worldwide. One in every four people aged 25 and older will face the consequences of this condition, which typically causes loss of limb function, among other disabilities. The proposed review analyzes the mechanisms of stroke and their influence on the disease outcome, highlighting the critical role of rehabilitation in promoting recovery of the upper limb (UL) and enhancing the quality of life of stroke survivors. Common outcome measures and the specific targeted UL features are described, along with emerging supplementary therapies found in the literature. Stroke survivors often develop compensatory strategies to cope with limitations in UL function, which must be detected and corrected during rehabilitation to facilitate long-term recovery. Recent research on the automated detection of compensatory movements has explored pressure, wearable, marker-based motion capture systems, and vision sensors. Although current approaches have certain limitations, they establish a strong foundation for future innovations in post-stroke UL rehabilitation, promoting a more effective recovery.

Transcranial stimulation has emerged as a non-invasive treatment that applies electrical currents and magnetic fields to regulate brain functions. Previous studies have shown that magnetic stimulation modulates the dynamics of charged molecules in biological systems. In some pathologies, once the electrical or magnetic field is applied directly to subjects, it can interact with, and alter, abnormally folded proteins, including amyloid-βpeptides and their aggregates, reducing cognitive impairments. While our understanding of the molecular mechanisms underlying the interaction between amyloid-βpeptide and the physical forces generated by electrical or magnetic stimulation remains unclear, observations show that these stimuli exert attractive and repulsive forces while interacting with the charged groups of peptide side chains as well as lipids. These interactions influence hydrophobic packing and secondary structure, ultimately inducing alterations in aggregation kinetics. The study of structural models of amyloidogenic proteins aids in understanding the mechanisms involved in the protein aggregation process and suggests possible therapeutic applications. This review examines proposed molecular mechanisms to explain the modulatory effects of external electromagnetic fields on the dynamics of proteins and their complexes that regulate pathological processes associated with amyloid-βpeptide fibrillation.

The measurement of small bowel length (SBL) is crucial in clinical contexts such as surgical planning, assessment of nutritional absorption and management of conditions like short bowel syndrome (SBS) and Crohn's disease (CD). However, the literature reports substantial variations in measurements of average SBL, influenced by a multitude of methodological and patient-specific factors. The present review provides a comprehensive analysis of existing methodologies for SBL measurement, including intraoperative and radiologic approaches, detailing their strengths, limitations, and sources of error. The key factors influencing measurement variability are discussed, including methodological differences related to the measurement tool (e.g. intraoperative vs. imaging-based), bowel preparation process (e.g. stretching of the bowel), starting reference points. Additionally, inter-individual characteristics (e.g. height, BMI, sex) and population-specific factors (e.g. patients with SBS or CD) are assessed for their contribution to SBL variability. The aim pertains to informing clinical practice by providing a critical evaluation of measurement techniques and variability factors that impair standardized measurements of SBL to support research for clinical practice.

Articular cartilage exhibits a remarkable mechanical and biological performance, which allows it to withstand high stresses and strains with minimal deformation, lasting decades of continuous use without failure. Upon damage, its self-repair is naturally difficult, being its regeneration a serious challenge today with current therapies failing in restoring the natural environment of this tissue. The present review delves deeply into the biomechanical functioning of articular cartilage, giving special attention to the interplay between its structure and composition with its mechanical behaviour at both tissue and cellular levels. The mechanisms by which articular cartilage responds to injury are highlighted to comprehend how this tissue is naturally damaged and how it could be regenerated, considering its native functioning. The current options for clinical evaluation and treatment are summarized. Drawing inspiration from the natural environment of articular cartilage and the mechanisms responsible for its health homeostasis, the application of optical and acoustic stimulation is proposed as mechanobiological solutions for promoting cartilage regeneration, followed by a final discussion on its current challenges and future perspectives. This review highlights the articular cartilage mechanical and biological functioning at both tissue and cellular level, elucidating strategies and challenges of articular cartilage regeneration in clinical research.

Articular cartilage is a porous, soft tissue present in the synovial joints that distributes the load and lubricate the joint for smooth body movements. Arthritis or joint diseases lead to cartilage degeneration. However, the triggering factors of these joint diseases are still strongly debated, with uncertainties about the key mechanisms and the mechanochemical and biological interactions that make this a very complex interdisciplinary problem. Nonetheless, mechanical stresses and improper lubrication are widely accepted as important contributors to cartilage degeneration. Hence, this review paper focuses on the friction, lubrication, and biomechanical aspects that affect cartilage function and are, therefore, linked to its degeneration. Further, cartilage lubrication theories that have been proposed to study ultra-low friction of cartilage will be discussed. Over the past decade, there has been significant advancement in understanding cartilage rehydration and how different activities keep cartilage lubricated; these will be reviewed together with the advances in experimental and modelling techniques that have enabled recent breakthroughs in our understanding. The need for new and improved methodologies in experimental and modelling work to deepen our understanding of cartilage biomechanics across the scales, as well as its evolution and degeneration will be discussed. Finally, with the widespread use of artificial intelligence (AI) and machine learning (ML) in scientific research, this paper explores the avenues in which AI and ML can contribute to enhancing the ongoing research on cartilage. .

The use ofE. colifor the expression of various collagen-like triple helical protein constructs has continued to develop significantly, and certain commercially made proteins are now available. The use of auxotroph designs to assist in the expression of hydroxylated proteins is an important development. A range of other new constructs have been described, including those that contain a segment of a natural collagen sequence and those that are based on collagen-like proteins from prokaryotes, especially the Scl2 protein fromStreptococcus pyogenes. The other constructs that have gained increased attention are those where multiple copies, often 16, of a small native collagen sequence are expressed as tandem repeated sequences, with these being of particular interest for biomedical applications. Ascertaining which construct is being used, however, can create difficulties when the same acronym is used for different constructs, and many are frequently described as 'humanized' even though no sequence changes have been included to make the construct resemble a human sequence more closely.

Could the next major advancement in cancer therapy stem from utilizing the body's own cells to precisely deliver potent anti-cancer agents directly to tumors? This innovative strategy, known as cell-drug conjugates (CDCs), represents a transformative approach to targeted cancer treatment by leveraging the inherent biological properties of cells. Leveraging the inherent biological properties of cells, these conjugates enable highly specific drug delivery and enhance therapeutic efficacy. Through mechanisms such as chemotaxis and immune evasion, CDCs can transport anticancer agents across biological barriers and selectively accumulate within the tumor microenvironment, facilitating precision therapy. Various cell types, including red blood cells, stem cells, and immune cells, serve as potential carriers in these systems, each possessing unique biological characteristics and antitumor ability. At present, there are few reviews on the preparation and function of CDCs in cancer therapy. This review systematically explores CDC applications in cancer therapy, including targeting mechanisms, fabrication strategies,in vivopharmacology, and clinical advancements. Furthermore, the review examines the technical challenges associated with this innovative drug delivery and therapeutic strategy, while also evaluating its potential for clinical translation.