scholarly journals Tissue Engineering of the Penis

2011 ◽  
Vol 11 ◽  
pp. 2567-2578 ◽  
Author(s):  
Manish N. Patel ◽  
Anthony Atala

Congenital disorders, cancer, trauma, or other conditions of the genitourinary tract can lead to significant organ damage or loss of function, necessitating eventual reconstruction or replacement of the damaged structures. However, current reconstructive techniques are limited by issues of tissue availability and compatibility. Physicians and scientists have begun to explore tissue engineering and regenerative medicine strategies for repair and reconstruction of the genitourinary tract. Tissue engineering allows the development of biological substitutes which could potentially restore normal function. Tissue engineering efforts designed to treat or replace most organs are currently being undertaken. Most of these efforts have occurred within the past decade. However, before these engineering techniques can be applied to humans, further studies are needed to ensure the safety and efficacy of these new materials. Recent progress suggests that engineered urologic tissues and cell therapy may soon have clinical applicability.

2020 ◽  
Vol 27 (31) ◽  
pp. 5189-5212 ◽  
Author(s):  
Li-Juan Yi ◽  
Jun-Feng Li ◽  
Ming-Guo Ma ◽  
Ying-Jie Zhu

In the past several decades, various types of nanostructured biomaterials have been developed. These nanostructured biomaterials have promising applications in biomedical fields such as bone repair, tissue engineering, drug delivery, gene delivery, antibacterial agents, and bioimaging. Nanostructured biomaterials with high biocompatibility, including calcium phosphate, hydroxyapatite, and calcium silicate, are ideal candidates for drug delivery. This review article is not intended to offer a comprehensive review of the nanostructured biomaterials and their application in drug delivery but rather presents a brief summary of the recent progress in this field. Our recent endeavors in the research of nanostructured biomaterials for drug delivery are also summarized. Special attention is paid to the synthesis and properties of nanostructured biomaterials and their application in drug delivery with the use of typical examples. Finally, we discuss the problems and future perspectives of nanostructured biomaterials in the drug delivery field.


2004 ◽  
Vol 71 ◽  
pp. 193-202 ◽  
Author(s):  
David R Brown

Prion diseases, also referred to as transmissible spongiform encephalopathies, are characterized by the deposition of an abnormal isoform of the prion protein in the brain. However, this aggregated, fibrillar, amyloid protein, termed PrPSc, is an altered conformer of a normal brain glycoprotein, PrPc. Understanding the nature of the normal cellular isoform of the prion protein is considered essential to understanding the conversion process that generates PrPSc. To this end much work has focused on elucidation of the normal function and activity of PrPc. Substantial evidence supports the notion that PrPc is a copper-binding protein. In conversion to the abnormal isoform, this Cu-binding activity is lost. Instead, there are some suggestions that the protein might bind other metals such as Mn or Zn. PrPc functions currently under investigation include the possibility that the protein is involved in signal transduction, cell adhesion, Cu transport and resistance to oxidative stress. Of these possibilities, only a role in Cu transport and its action as an antioxidant take into consideration PrPc's Cu-binding capacity. There are also more published data supporting these two functions. There is strong evidence that during the course of prion disease, there is a loss of function of the prion protein. This manifests as a change in metal balance in the brain and other organs and substantial oxidative damage throughout the brain. Thus prions and metals have become tightly linked in the quest to understand the nature of transmissible spongiform encephalopathies.


2019 ◽  
Vol 19 (1) ◽  
pp. 4-16 ◽  
Author(s):  
Qihui Wu ◽  
Hanzhong Ke ◽  
Dongli Li ◽  
Qi Wang ◽  
Jiansong Fang ◽  
...  

Over the past decades, peptide as a therapeutic candidate has received increasing attention in drug discovery, especially for antimicrobial peptides (AMPs), anticancer peptides (ACPs) and antiinflammatory peptides (AIPs). It is considered that the peptides can regulate various complex diseases which are previously untouchable. In recent years, the critical problem of antimicrobial resistance drives the pharmaceutical industry to look for new therapeutic agents. Compared to organic small drugs, peptide- based therapy exhibits high specificity and minimal toxicity. Thus, peptides are widely recruited in the design and discovery of new potent drugs. Currently, large-scale screening of peptide activity with traditional approaches is costly, time-consuming and labor-intensive. Hence, in silico methods, mainly machine learning approaches, for their accuracy and effectiveness, have been introduced to predict the peptide activity. In this review, we document the recent progress in machine learning-based prediction of peptides which will be of great benefit to the discovery of potential active AMPs, ACPs and AIPs.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 287
Author(s):  
Ye Lin Park ◽  
Kiwon Park ◽  
Jae Min Cha

Over the past decades, a number of bone tissue engineering (BTE) approaches have been developed to address substantial challenges in the management of critical size bone defects. Although the majority of BTE strategies developed in the laboratory have been limited due to lack of clinical relevance in translation, primary prerequisites for the construction of vascularized functional bone grafts have gained confidence owing to the accumulated knowledge of the osteogenic, osteoinductive, and osteoconductive properties of mesenchymal stem cells and bone-relevant biomaterials that reflect bone-healing mechanisms. In this review, we summarize the current knowledge of bone-healing mechanisms focusing on the details that should be embodied in the development of vascularized BTE, and discuss promising strategies based on 3D-bioprinting technologies that efficiently coalesce the abovementioned main features in bone-healing systems, which comprehensively interact during the bone regeneration processes.


Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Traian V. Chirila

Fibroin is a fibrous protein that can be conveniently isolated from the silk cocoons produced by the larvae of Bombyx mori silk moth. In its form as a hydrogel, Bombyx mori silk fibroin (BMSF) has been employed in a variety of biomedical applications. When used as substrates for biomaterial-cells constructs in tissue engineering, the oxygen transport characteristics of the BMSF membranes have proved so far to be adequate. However, over the past three decades the BMSF hydrogels have been proposed episodically as materials for the manufacture of contact lenses, an application that depends on substantially elevated oxygen permeability. This review will show that the literature published on the oxygen permeability of BMSF is both limited and controversial. Additionally, there is no evidence that contact lenses made from BMSF have ever reached commercialization. The existing literature is discussed critically, leading to the conclusion that BMSF hydrogels are unsuitable as materials for contact lenses, while also attempting to explain the scarcity of data regarding the oxygen permeability of BMSF. To the author’s knowledge, this review covers all publications related to the topic.


2020 ◽  
Vol 8 (21) ◽  
pp. 6069-6081
Author(s):  
Ao Xiong ◽  
Yijun He ◽  
Liang Gao ◽  
Guoqing Li ◽  
Jian Weng ◽  
...  

Over the past few years, tissue-engineering technology provided a new direction for bone defects therapy, which involved developing applicable biological materials composite with seed cells to repair bone defects tissue.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3310
Author(s):  
Shengda Liu ◽  
Jiayun Xu ◽  
Xiumei Li ◽  
Tengfei Yan ◽  
Shuangjiang Yu ◽  
...  

In the past few decades, enormous efforts have been made to synthesize covalent polymer nano/microstructured materials with specific morphologies, due to the relationship between their structures and functions. Up to now, the formation of most of these structures often requires either templates or preorganization in order to construct a specific structure before, and then the subsequent removal of previous templates to form a desired structure, on account of the lack of “self-error-correcting” properties of reversible interactions in polymers. The above processes are time-consuming and tedious. A template-free, self-assembled strategy as a “bottom-up” route to fabricate well-defined nano/microstructures remains a challenge. Herein, we introduce the recent progress in template-free, self-assembled nano/microstructures formed by covalent two-dimensional (2D) polymers, such as polymer capsules, polymer films, polymer tubes and polymer rings.


Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 219-229 ◽  
Author(s):  
G K Yasuda ◽  
G Schubiger ◽  
B T Wakimoto

Abstract The vast majority of known male sterile mutants of Drosophila melanogaster fail to produce mature sperm or mate properly. The ms(3) K81(1) mutation is one of a rare class of male sterile mutations in which sterility is caused by developmental arrest after sperm entry into the egg. Previous studies showed that males homozygous for the K81(1) mutation produce progeny that arrest at either of two developmental stages. Most embryos arrest during early nuclear cycles, whereas the remainder are haploid embryos that arrest at a later stage. This description of the mutant phenotype was based on the analysis of a single allele isolated from a natural population. It was therefore unclear whether this unique paternal effect phenotype reflected the normal function of the gene. The genetic analysis and initial molecular characterization of five new K81 mutations are described here. Hemizygous conditions and heteroallelic combinations of the alleles were associated with male sterility caused by defects in embryogenesis. No other mutant phenotypes were observed. Thus, the K81 gene acted as a strict paternal effect gene. Moreover, the biphasic pattern of developmental arrest was common to all the alleles. These findings strongly suggested that the unusual embryonic phenotype caused by all five new alleles was due to loss of function of the K81+ gene. The K81 gene is therefore the first clear example of a strict paternal effect gene in Drosophila. Based on the embryonic lethal phenotypes, we suggest that the K81+ gene encodes a sperm-specific product that is essential for the male pronucleus to participate in the first few embryonic nuclear divisions.


2018 ◽  
Vol 14 (4) ◽  
pp. 734-747 ◽  
Author(s):  
Constance de Saint Laurent

There has been much hype, over the past few years, about the recent progress of artificial intelligence (AI), especially through machine learning. If one is to believe many of the headlines that have proliferated in the media, as well as in an increasing number of scientific publications, it would seem that AI is now capable of creating and learning in ways that are starting to resemble what humans can do. And so that we should start to hope – or fear – that the creation of fully cognisant machine might be something we will witness in our life time. However, much of these beliefs are based on deep misconceptions about what AI can do, and how. In this paper, I start with a brief introduction to the principles of AI, machine learning, and neural networks, primarily intended for psychologists and social scientists, who often have much to contribute to the debates surrounding AI but lack a clear understanding of what it can currently do and how it works. I then debunk four common myths associated with AI: 1) it can create, 2) it can learn, 3) it is neutral and objective, and 4) it can solve ethically and/or culturally sensitive problems. In a third and last section, I argue that these misconceptions represent four main dangers: 1) avoiding debate, 2) naturalising our biases, 3) deresponsibilising creators and users, and 4) missing out some of the potential uses of machine learning. I finally conclude on the potential benefits of using machine learning in research, and thus on the need to defend machine learning without romanticising what it can actually do.


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