作为生物学和医学领域的科学家，您精通英语和简体中文。将以下段落准确地翻译成符合学术论文语言风格的简体中文，并保持原陈述的结构： 作为天然纳米载体，外泌体具有低免疫原性、非细胞毒性和靶向传递能力等特点，相对于合成纳米载体具有优势。最近，外泌体作为疾病诊断标志物表现出极大的潜力，并被认为是一种有前景的无细胞疗法。工程化外泌体显著提高了递送治疗药物的效果和精确性，并目前广泛应用于针对肿瘤学、炎症性疾病和退行性疾病等各种疾病的靶向治疗研究中。特别是，工程化外泌体实现了治疗药物装载、靶向修饰、躲避单核吞噬细胞系统吞噬、智能控制和生物成像等功能，并在近年来作为多功能纳米递送平台取得了发展。通过装载外泌体递送的生物活性支架可显著增加外泌体保持、延长释放和增强功效。该方法已从常规水凝胶发展到纳米复合水凝胶、纳米纤维水凝胶和3D打印等，使物理和生物性能得到了改善，有效解决了天然支架的局限性。此外，通过口服参与肠道菌群重塑的植物来源外泌体被认为是治疗肠道疾病的理想载体。因此，外泌体和外泌体作为纳米载体在治疗和诊断应用方面引起了极大的兴趣。本综述概述了外泌体的生物发生、组成和分离方法。此外，它还研究了外泌体在肿瘤、退行性疾病和炎症性疾病等各种疾病中的病理和诊断机制。此外，本综述还强调了肠道微生物源性外泌体的重要性。工程化外泌体和生物活性支架载荷的外泌体递送策略和具体应用进一步总结，尤其是一些新技术，如大规模载荷技术、大分子载荷技术、多功能纳米递送平台的发展和纳米支架载荷的外泌体递送。讨论了植物来源外泌体在治疗与肠道相关疾病方面的潜在益处。此外，从临床和临床观点总结了外泌体基础纳米载体在疾病诊断和治疗方面的挑战、机遇和前景。 © 2023 Zou等

Exosomes, as natural nanocarriers, characterized with low immunogenicity, non-cytotoxicity and targeted delivery capability, which have advantages over synthetic nanocarriers. Recently, exosomes have shown great potential as diagnostic markers for diseases and are also considered as a promising cell-free therapy. Engineered exosomes have significantly enhanced the efficacy and precision of delivering therapeutic agents, and are currently being extensively employed in targeted therapeutic investigations for various ailments, including oncology, inflammatory disorders, and degenerative conditions. Particularly, engineered exosomes enable therapeutic agent loading, targeted modification, evasion of MPS phagocytosis, intelligent control, and bioimaging, and have been developed as multifunctional nano-delivery platforms in recent years. The utilization of bioactive scaffolds that are loaded with exosome delivery has been shown to substantially augment retention, extend exosome release, and enhance efficacy. This approach has advanced from conventional hydrogels to nanocomposite hydrogels, nanofiber hydrogels, and 3D printing, resulting in superior physical and biological properties that effectively address the limitations of natural scaffolds. Additionally, plant-derived exosomes, which can participate in gut flora remodeling via oral administration, are considered as an ideal delivery platform for the treatment of intestinal diseases. Consequently, there is great interest in exosomes and exosomes as nanocarriers for therapeutic and diagnostic applications. This comprehensive review provides an overview of the biogenesis, composition, and isolation methods of exosomes. Additionally, it examines the pathological and diagnostic mechanisms of exosomes in various diseases, including tumors, degenerative disorders, and inflammatory conditions. Furthermore, this review highlights the significance of gut microbial-derived exosomes. Strategies and specific applications of engineered exosomes and bioactive scaffold-loaded exosome delivery are further summarized, especially some new techniques such as large-scale loading technique, macromolecular loading technique, development of multifunctional nano-delivery platforms and nano-scaffold-loaded exosome delivery. The potential benefits of using plant-derived exosomes for the treatment of gut-related diseases are also discussed. Additionally, the challenges, opportunities, and prospects of exosome-based nanocarriers for disease diagnosis and treatment are summarized from both preclinical and clinical viewpoints.© 2023 Zou et al.