Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Nucleotide analogues (NAs) and interferon are still the first-line drugs for the treatment of chronic hepatitis B (CHB), but they still cannot completely eliminate covalently closed circular DNA (cccDNA) within hepatocytes. The clinical cure, or the disappearance of HBsAg, is the ideal goal of antiviral therapy. Although interferon therapy has a significantly greater HBsAg clearance rate and seroconversion rate than NAs, combination or sequential treatment can improve the HBsAg clearance rate and seroconversion rate to a certain extent, and only a small proportion of CHB patients can achieve clinical cure. Therefore, finding indications that predict clinical cure before and during antiviral treatment is crucial for identifying patients who are more likely to achieve HBsAg clearance at an early stage, improving clinical cure rates, and reducing treatment costs. This article reviews the research progress on predictive indicators of clinical cure of chronic hepatitis B in the past five years, explores the value of each indicator in predicting clinical cure, and provides a reference for optimizing CHB treatment strategies.

Objective:To explore the dosimetric characteristics of intensity modulated proton therapy (IMPT) and intensity modulated radiation therapy (IMRT) for typical abdominal and pelvic tumors.Methods:Three patients with abdominal and pelvic tumors (one case each of liver cancer, cervical cancer, and prostate cancer) admitted to Shandong Cancer Hospital and Institute from January to June 2024 were selected as the research subjects. IMPT and IMRT plans were designed for each case based on clinical target volume (CTV) and organs at risk (OARs) constraints. Dosimetric parameters, including conformity index (CI), homogeneity index (HI), and gradient index (GI) for target coverage, as well as OARs dose metrics, were evaluated. The volume of additional dose deposition in the body was compared by assessing regions receiving 10%, 30%, and 50% of the prescription dose.Results:For all three cases, IMRT plan demonstrated higher CI values (0.82, 0.81, and 0.86) compared to IMPT plan (0.61, 0.62, and 0.43). IMPT plan yielded lower HI values (0.053, 0.075, and 0.020) than IMRT plan (0.060, 0.120, and 0.080) and lower GI values (3.45, 2.63, and 3.80 vs. 7.28, 4.76, and 4.66 for IMRT plan). In liver cancer, IMPT plan reduced the D mean of normal liver tissues and right kidney by 37.8% and 78.5%, respectively, and decreased the D max of spinal cord by 13.2%. For cervical cancer, IMPT plan reduced the V 30 of the small bowel by 22.0%, D mean of the bladder, rectum and bone marrow by 15.7%, 14.3% and 12.6%, and spinal cord D max by 4.8%. In prostate cancer, IMPT plan lowered bladder and rectal D mean by 14.9% and 36.5%, respectively, but resulted in an increase of 35.3% and 6.1% in the D mean and V 40 of the left femoral head, respectively, and an increase of 23.6% and 10.8% in the D mean and V 40 of the right femoral head, respectively. IMPT plan reduced the volumes receiving 10%, 30%, and 50% of the prescription dose by 48.9%-64.8%, 22.0%-47.0%, and 22.0%-57.7%, respectively, compared to IMRT plan. Conclusions:Comparison between IMPT and IMRT plans for abdominopelvic tumors: IMPT plan offers advantages in reducing doses to normal organs such as the liver, kidneys, spinal cord, small intestine, rectum, and bladder. However, its advantage is less pronounced regarding the dose to the femoral heads. IMPT plan notably minimizes additional dose deposition within the body.

Nucleotide analogues (NAs) and interferon are still the first-line drugs for the treatment of chronic hepatitis B (CHB), but they still cannot completely eliminate covalently closed circular DNA (cccDNA) within hepatocytes. The clinical cure, or the disappearance of HBsAg, is the ideal goal of antiviral therapy. Although interferon therapy has a significantly greater HBsAg clearance rate and seroconversion rate than NAs, combination or sequential treatment can improve the HBsAg clearance rate and seroconversion rate to a certain extent, and only a small proportion of CHB patients can achieve clinical cure. Therefore, finding indications that predict clinical cure before and during antiviral treatment is crucial for identifying patients who are more likely to achieve HBsAg clearance at an early stage, improving clinical cure rates, and reducing treatment costs. This article reviews the research progress on predictive indicators of clinical cure of chronic hepatitis B in the past five years, explores the value of each indicator in predicting clinical cure, and provides a reference for optimizing CHB treatment strategies.

The concept of competency-based standardized residency training is gaining global popularity. However, the process of assessing, continuously evaluating, and conducting final competency evaluations remains challenging. The Milestones 2.0 system, developed by the Accreditation Council for Graduate Medical Education, provides a framework for evaluating competencies in radiation oncology residents. The core objective of this system is to assess sub-competencies within core competencies, categorizing them from novice to expert across 5 levels. Evaluation occurs every 6 months, with the expectation that all residents reach level 4 in all sub-competencies by the end of their training. This approach aims to enhance the standardization of residency evaluations across the United States. This article aims to analyze the Milestones 2.0 competency framework and explore its potential applicability and reference value for standardized radiation oncology residency training in China.

Due to advances in treatment methods, the survival rate and quality of life of cancer patients have been improved. Radiation-induced vascular injury (RIVI) is a common adverse reaction following radiotherapy, mainly manifested as capillary injury and atherosclerosis in the irradiated area. Radiotherapy induces RIVI in the cerebral vessels, carotid arteries, coronary arteries, and large arteries through mechanisms such as endothelial cell injury and senescence, oxidative stress and inflammatory responses, angiogenesis, and vascular remodeling. In this review research progress in the pathological features, pathophysiological mechanisms, clinical manifestations, prevention and treatment strategies of RIVI was summarized, aiming to provide insights for future research on RIVI.

Radiation-induced rectal injury (RRI) refers to inflammatory intestinal complications of patients with pelvic cavity, abdominal cavity and retroperitoneal tumor during or after radiotherapy, presenting symptoms such as diarrhea, abdominal pain, anal distension, bloody stool, etc. In severe cases, rectovaginal fistula, intestinal obstruction, canceration can occur, adversely affecting the quality of life of patients. The clinical factors of RRI involve total radiotherapy dose, tumor volume, radiotherapy mode and patient-related risk factors. The diagnosis mainly depends on imaging examinations (such as CT, MRI and ultrasound), endoscopy and laboratory examination. The mechanism of RRI is related to intestinal epithelial cell destruction, stem cell injury, microvascular changes and microbial flora imbalance. At present, there is no gold standard for RRI treatment, and the main measures include surgical treatment, internal medicine treatment, hyperbaric oxygen therapy and fecal microbiota transplantation, etc. In this article, the latest progress in the pathogenesis, diagnosis and treatment of RRI was reviewed.

Radiation-induced esophageal injury (RIEI) is a frequent complication following radiotherapy for thoracic and head-neck malignancies, which may lead to severe sequelae including esophageal stricture and perforation, adversely affecting patients' quality of life and therapeutic outcomes. With advancements in radiotherapy techniques — particularly the adoption of unconventional fractionation regimens, concurrent chemoradiotherapy, and combined molecular targeted / immunotherapy — the incidence of RIEI has been increasing. In this review, recent advances in understanding the pathogenesis, clinical manifestations, risk factors, and management strategies for RIEI were comprehensively summarized. Current therapeutic approaches have evolved beyond conventional anti-inflammatory and nutritional support to include novel interventions such as targeted therapy, free radical scavengers, and microbiota modulation, etc. Future research should prioritize the development of optimized, individualized prevention and treatment protocols to mitigate RIEI risk and improve patient prognosis.

The global incidence of head and neck cancer (HNC) is rising, with over 60% of patients presenting at a locally advanced stage. Radiotherapy remains a cornerstone of HNC treatment, and advancements in modern techniques and concurrent chemotherapy have improved local control and survival rates of HNC patients. However, these benefits also bring challenges in the management of toxicities. Due to the proximity of salivary glands and tumors, especially the highly radiosensitive parotid and submandibular glands, this condition is among the most common adverse effects of radiotherapy. Radiation damages acinar cells and ducts, causing glandular atrophy, fibrosis, and reduced saliva secretion, thereby leading to xerostomia and related complications. The risk and severity of injury are associated with the radiation dose and volume affecting the glands. Prevention and management strategies emphasize precise radiotherapy planning, target optimization, and supportive care. Emerging multimodal imaging techniques offer potential for non-invasive prediction and early diagnosis and treatment of radiation-induced salivary gland injury. Future research in regenerative medicine, tissue engineering, and molecular biology aims to elucidate molecular mechanisms, such as signaling pathways and genomics, facilitating personalized strategies to mitigate radiotherapy-induced toxicities and enhance the quality of life of patients.

Osteoradionecrosis of the jaws (ORNJ) is among the most severe oral complications following radiotherapy for head and neck tumors. It is essentially a form of pathological necrosis of the jawbone induced by radiation therapy. ORNJ is defined as bone damage, primarily characterized by inflammation and necrosis, occurring in the jawbone within the irradiated area and accompanied by soft tissue injury, persisting for more than 3 months without spontaneous healing. Diagnosis requires exclusion of other potential etiologies, including primary tumor recurrence, medication-related osteonecrosis, and radiation-induced neoplasms of the jawbone, etc. In this review, recent advances in the epidemiology, risk factors, diagnosis, classification and staging, dosimetric parameters, pathogenesis, treatment, and prevention of radiation-induced osteonecrosis of the jaws were summarized.