Due to patient compliance and convenience, oral medication is likely the most common and acceptable method of drug administration. However, traditional dosage forms such as tablets or capsules may lead to low drug bioavailability and poor therapeutic efficiency. Therefore, with advancements in material science and micro/nano manufacturing technology, various carriers have been developed to enhance drug absorption in the gastrointestinal tract. In this context, we initially discuss the key biological factors that hinder drug transport and absorption (including anatomical, physical, and biological factors). Building on this foundation, recent progress in both conventional and innovative oral drug delivery routes aimed at improving drug bioavailability and targeting is reviewed. Finally, we explore future prospects for oral drug delivery systems as well as potential challenges in clinical translation.

Traditional Chinese medicine (TCM) has historically played a pivotal role in the prevention and treatment of warm diseases, establishing a comprehensive theoretical framework that underpins its practices. The distinctive and indispensable contributions of aromatic Chinese herbs in dispelling harmful influences and mitigating the spread of these diseases are well recognized; however, further investigation is warranted to elucidate their systematic properties and regularities, and the theory of aromatic Chinese herbs in preventing and treating warm diseases still needs to be comprehensively summarized. This study employs the principles rooted in TCM, with particular emphasis on the framework for warm diseases. An analysis of the disease mechanisms, transmission dynamics, and preventive strategies is conducted during the early stage of infection, throughout the course of the disease, and in the post-illness phase. Furthermore, the characteristics and applications of aromatic Chinese herbs are integrated with insights drawn from modern pharmacological research to explore their specific roles in the prevention and management of warm diseases. The utilization of aromatic Chinese herbs manifests in a variety of therapeutic effects: aromatic medicinals purging filth and dispelling pathogens for preventing epidemic disease, aromatic medicinals regulation for relieving superficies syndrome and dispersing evils, aromatic medicinals ventilation the lung to relieve cough and asthma, aromatic medicinals resolving the dampness to awaken the spleen and stomach, aromatic medicinals opening the orifices to restore consciousness, aromatic and pungent medicinals to regulate qi, aromatic medicinals dredging the vessels to activate blood circulation and dissipate blood stasis, and aromatic medicinals clearing latent heat from the yin level. These properties facilitate tailored approaches to address the diverse manifestations of warm diseases and their associated symptoms, providing clear guidance for clinical application to achieve pre-disease prevention, active disease treatment, complication prevention, and post-recovery relapse avoidance. The use of aromatic Chinese herbs in preventing and treating warm diseases demonstrates theoretical, practical, systematic, and regular characteristics. The theory of the properties of aromatic Chinese herbs has been expanded and sublimated in clinical practice, and its scientific connotation has been expounded in modern research. Under the guidance of the theory of treatment based on syndrome differentiation, and by taking into account the distinct stages and pathologies of warm diseases, the rational selection of aromatic Chinese herbs can improve the clinical efficacy.

Objective: To investigate the therapeutic effect of patchouli alcohol on mice with lung-heat syndrome based on the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt)/nuclear factor-kappa B(NF-κB) signaling pathway. Methods: First, network pharmacology was used to predict the potential targets of patchouli alcohol in the treatment of lung-heat syndrome, and a "component-disease-key target" network was constructed for pathway analysis. Then, 40 BALB/c mice were assigned to the normal, lung-heat model, honeysuckle, and low-dose and high-dose patchouli alcohol groups. All groups, except the blank group, were intranasally infected with 50 μL (103 TCID50) of influenza virus solution. After two hours of infection, mice were treated once a day for seven consecutive days. The therapeutic mechanism of patchouli alcohol was explored by measuring pulmonary inflammatory factors, the PI3K/Akt/NF-κB pathway, hypothalamic fever markers (PGE2, cAMP, cGMP levels), rectal temperature, and tissue energy metabolism. Results: Network pharmacology identified 135 target genes related to patchouli alcohol and lung-heat syndrome, with the key targets being STAT3, H1F1A, and NF-κB1. In animal experiments, patchouli alcohol significantly alleviated influenza virus-induced lung inflammatory damage in mice with lung-heat syndrome, inhibited the expression of TNF-α and IL-6 in lung tissues(P<0.01), and suppressed the activation of the PI3K/Akt/NF-κB pathway. It also reduced hypothalamic levels of PGE2 and cAMP(P<0.01), suppressed the increase in rectal temperature, significantly decreased liver glycogen and pyruvate levels(P<0.01), and increased the activities of SDH, LDH, and Na+ -K+ -ATPase in the liver(P<0.01) Conclusion Patchouli alcohol improves the symptoms of lung-heat syndrome in mice by inhibiting the activation of the PI3K/Akt/NF-κB pathway, reducing proinflammatory cytokines and inflammatory damage, and regulating hypothalamic fever markers and energy metabolism.

Objective: To investigate the biological effects of carvacrol on rats with stomach-heat and stomach-cold and its regulation on transient receptor potential(TRP) channels in rats with stomach-heat, and to study the cold and heat properties of carvacrol and its possible mechanism. Methods: According to the random number method, 100 SD rats were divided into stomach-heat blank group, stomach-heat model group, Coptidis Rhizoma group, stomach-heat low-dose and high-dose carvacrol group, stomach-cold blank group, stomach-cold model group, Baked ginger group, stomach-cold low-dose group and high-dose carvacrol group, 10 rats in each group. The rat model of stomach-heat was established by intragastric administration of pepper aqueous solution (0.80 g/kg) and anhydrous ethanol, and the rat model of stomach-cold was established by intragastric administration of water extract of Anemarrhena asphodeloides and sodium hydroxide (10.40 g/kg). On the day of modeling, the rats in the Baked ginger group were given Baked ginger decoction (0.78 g/kg), and the rats in the Coptidis Rhizoma group were given Coptidis Rhizoma decoction (0.43 g/kg).The stomach-cold and stomach-heat low-dose group of carvacrol was given carvacrol emulsion (40 mg/kg), high-dose group was given carvacrol emulsion (80 mg/kg).All rats of the blank and model groups were given the equal volume of emulsion prepared by 5% dimethyl sulfoxide, 1% Tween 80, 1% polyethylene glycol 400, and 93% normal saline, once a day, for 7 days. The general condition of rats was observed and the body mass was recorded. The pathological morphology of gastric tissue was observed by hematoxylin-eosin staining. The changes of material and energy metabolism, cyclic nucleotide (cAMP), thyroid hormone and gastrointestinal hormone in each group were determined by enzyme-linked immunosorbent assay. The expression levels of transient receptor potential vanilloid subtype 1 (TRPV1), transient receptor potential channel M8 (TRPM8) and uncoupling protein-1 (UCP1) in rats with gastric fever were detected by Western blotting. Results: Compared with the stomach-heat blank group, the body mass of rats in the stomach-heat model group decreased at the fifth and seventh day (P<0.05). The contents (or ratio) of hepatic glycogen (HGlyc), total cholesterol (TC), triglyceride (TG), and vasoactive intestinal peptide (VIP) were decreased (P<0.05), and Na+ -K+ -ATPase, Ca2+ -Mg2+ -ATPase, cytochrome C oxidase (COX), NADH dehydrogenase (ND), cyclic adenosine phosphate (cAMP), cAMP/cyclic guanosine phosphate (cGMP), triiodothyronine (T3), thyroxine (T4), gastrin (GAS), motilin (MTL), and α-amylase (α-AMS) all increased (P<0.05). Compared with the stomach-heat model group, the body mass of rats in the Coptidis Rhizoma group decreased at the third, fifth, and seventh day, the contents (or ratio) of HGlyc, TC, TG, VIP and α-AMS were increased, and Na+ -K+ -ATPase, COX, ND, cAMP, cAMP/cGMP, T3, T4, and GAS all decreased (P<0.05). The body mass of rats in the stomach-heat low-dose carvacrol group decreased at the seventh day. The contents (or ratio) of HGlyc, TC, and VIP were increased, Na+ -K+ -ATPase, COX, ND, cAMP, cAMP/cGMP, T3, T4, and MTL all decreased, the expression of TRPV1 and UCP1 in gastric tissue decreased, while TRPM8 increased (P<0.05) in rats of the stomach-heat low-dose and high-dose carvacrol groups. Compared with the stomach-cold blank group, the body mass of rats in the stomach-cold model group decreased at the third, fifth, and seventh day, the contents (or ratio) of HGlyc, TC, TG, α-AMS, and VIP all increased, while Na+ -K+ -ATPase, Ca2+ -Mg2+ -ATPase, COX, ND, cAMP, cAMP/cGMP, T3, T4, GAS, and MTL all decreased (P<0.05). Compared with the stomach-cold model group, the body mass of rats in the Baked ginger group was increased at the seventh day, and the contents (or ratio) of HGlyc, VIP, and α-AMS all decreased, while Na+ -K+ -ATPase, COX, ND, cAMP/cGMP, T3, T4, GAS, and MTL all increased (P<0.05). The contents of HGlyc, cAMP, α-AMS, and VIP of rats in the stomach-cold low and high-dose carvacrol group all decreased (P<0.05). TG in the stomach-cold low-dose carvacrol group was increased. TC, Ca2+ -Mg2+ -ATPase, and cGMP all increased, while cAMP/cGMP decreased (P<0.05) in the high-dose carvacrol group. Conclusion In this study, the rat model of stomach-cold and stomach-heat were successfully established by using cold and heat factors. The result showed that carvacrol had a certain inhibitory effect on body mass, material energy metabolism, cyclic nucleotide level, thyroid hormone and gastrointestinal function in rats with stomach-heat, indicating that the drug was cold. Carvacrol′s cold medicinal property could be biologically explained by TRPV1 activation, UCP1 induction, and TRPM8 suppression.

Objective To investigate the epidemiological characteristics of cross-county imported dengue fever cases within Yunnan province in 2023, so as to provide insights into formulation of preventive and control measures for intra-provincial spread of dengue fever. Methods All data pertaining cross-county imported dengue fever cases within Yunnan Province in 2023 were collected, and the temporal, regional and population distributions of the cases were descriptively analyzed. Results A total of 1 664 intra-provincial cross-county imported dengue fever cases were reported in 95 counties (cities, districts) cross 16 profectures (cities) in Yunnan Province in 2023, accounting for 12.34% of total cases in the province. Cross-county imported dengue fever cases were predominantly reported during the period between August and October (1 516 cases, 91.11% of total cases), and peaked in September (659 cases), with a single-day peak on October 8 (36 cases). During the period from September 4 to 10, five counties (cities) with local dengue fever epidemics, including Jinghong City of Xishuangbanna Dai Autonomous Prefecture, Gengma Dai and Wa Autonomous County of Lincang City, Ruili City of Dehong Dai and Jingpo Autonomous Prefecture, Mengla Coun ty of Xishuangbanna Dai Autonomous Prefecture, and Zhenkang County of Lincang City, exported 165 cross-county imported dengue fever cases to the rest of the province. Among the 1 644 intra-provincial cross-county imported dengue fever cases, the male to female ratio was 1.40∶1.00, and 1 329 cases were at ages of 15 to 55 years (79.87%), with farmers as the predominant occupation (886 cases, 53.25%). The top 5 counties (cities/districts) reporting the highest number of intra-provincial cross-county imported dengue fever cases included Simao District (266 cases) and Lancang Lahu Autonomous County (118 cases) of Pu’er City, Mengla County (91 cases) and Menghai County (91 cases) of Xishuangbanna Dai Autonomous Prefecture, and Mangshi City (73 cases) of Dehong Dai and Jingpo Autonomous Prefecture, which accounting for 38.40% of total imported cases. These intra-provincial cross-county imported dengue fever cases originated from 7 counties (cities/districts) in 4 prefectures (cities), including 1 261 cases (76.70%) from Jinghong City of Xishuangbanna Dai Autonomous Prefecture, 224 cases (13.63%) from Ruili City of Dehong Dai and Jingpo Autonomous Prefecture, 103 cases (6.27%) from Gengma Dai and Wa Autonomous County of Lincang City, 31 cases (1.89%) from Mengla County of Xishuangbanna Dai Autonomous Prefecture, 30 cases (1.82%) from Zhenkang County of Lincang City, 10 cases (0.61%) from Cangyuan Wa Autonomous County of Lincang City, and 5 cases (0.30%) from Mohan-Boten Economic Cooperation Zone of Kunming City. In addition, local dengue fever epidemics following intra-provincial cross-county importation of dengue fevers cases in Simao District, Jinggu Dai and Yi Autonomous County, Mangshi City, Longchuan County, and Cangyuan Wa Autonomous County. Conclusions Farmers and students are high-risk populations for intra-provincial cross-county imported dengue fever cases in Yunnan Province, and health education pertaining personal protection against dengue fever should be strengthened among these high-risk populations by governments at all levels. There is a high risk of local out-break of dengue fever following continuous introduction of intra-provincial cross-county imported cases. Standardized management of intra-provincial cross-county imported dengue fever cases should be reinforced to reduce the risk of local epidemics.

Aromatic traditional Chinese medicine(TCM) has played an important role against epidemics and viruses, and volatile components are the main components that exert the pharmacological effects of aromatic TCM. By screening the related monomer components in aromatic TCM against epidemic and viruses and analyzing and endowing TCM with medicinal properties based on its clinical application and pharmacological research according to the theoretical thinking of TCM, the key technical issues of compatibility of TCM monomer components were solved from a theoretical perspective, providing new ideas and methods for screening raw materials and formulas for the development of new TCM drugs. Based on the conditions of antiviral activity, clinical application foundation, definite therapeutic effect, and high safety, a gradient screening of aromatic TCM was carried out. Firstly, 30 aromatic TCM were screened from anti-epidemic literature and clinical trial formulas, and seven volatile monomers were further screened from them. Then, four monomer components with significant effects, namely patchouli alcohol, carvacrol, p-cymene, and eucalyptol were screened. By adopting the "four-step method for a systematic study of TCM properties", the four monomer components were endowed with medicinal properties, and compatibility and combination studies were conducted to explore the theoretical basis of monomer formulas and form monomer formulas guided by TCM theory. The screening results of volatile monomers in aromatic TCM against viral pneumonia included patchouli alcohol, carvacrol, p-cymene, and eucalyptol. The medicinal properties and compatibility theory of volatile monomer components in TCM were explored. Patchouli alcohol was the main herb, with a cool and pungent nature. It entered the lung meridian to dispel evil Qi and has the effects of aromatization, detoxification, and epidemic prevention. Carvacrol was a minister drug with a cool and pungent taste. It had the effects of aromatizing, moistening, and dissolving the exterior, as well as strengthening the spleen and stomach. p-Cymene was an adjunctive medicine with a mild and pungent nature. It entered the lungs and kidneys and had the effects of aromatic purification, cough relief, and asthma relief. Eucalyptol was also an adjunctive medicine with a pungent and warm taste. It had the functions of aromatic purification, cough relief, phlegm reduction, and pain relief. The combination of the four medicines had the effects of aromatizing, moistening, detoxifying, and epidemic prevention, as well as relieving cough and asthma and strengthening the spleen and stomach. They were used to treat viral pneumonia caused by upper respiratory tract viral infections, with symptoms such as chest tightness, cough, wheezing, fatigue, nasal congestion, runny nose, nausea, and vomiting. This study has laid a literature and theoretical foundation for further drug efficacy verification experiments, compatibility efficacy experiments, and subsequent product development and clinical applications, and it serves as an innovative practice that combines literature research, theoretical research, experimental research, and clinical practice to develop new products.
Drugs, Chinese Herbal/therapeutic use* ; Antiviral Agents/pharmacology* ; Humans ; Pneumonia, Viral/virology* ; Medicine, Chinese Traditional ; Volatile Organic Compounds/pharmacology* ; Animals

This paper aims to investigate the influence of eucalyptol on the biological effects of spleen cold and spleen heat syndromes in rats and its regulation of transient receptor potential vanilloid 1(TRPV1), transient receptor potential melastatin 8(TRPM8), and uncoupling protein 1(UCP1), so as to explore the cold-heat properties of eucalyptol. Rats were randomly divided into groups as follows: blank group, spleen cold syndrome model group, spleen cold syndrome+Atractylodis Rhizoma group, spleen cold syndrome + low-dose eucalyptol group, and spleen cold syndrome+high-dose eucalyptol group, as well as blank group, spleen heat syndrome model group, spleen heat syndrome+Coptidis Rhizoma group, spleen heat syndrome + low-dose eucalyptol group, and spleen heat syndrome + high-dose eucalyptol group. Spleen cold and spleen heat syndromes were induced by disorders of hunger and satiety combined with bitter cold drugs, as well as a high-fat diet combined with liquor. Except for the blank and model groups, the other groups were administered once a day during the modeling process for 14 consecutive days. The general condition and body weight of rats in each group were observed, and the histopathological morphology of the gastric antrum and small intestine was observed by hematoxylin-eosin(HE) staining. The contents of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), Na~+-K~+-ATPase, total cholesterol(TC), triglyceride(TG), gastrin(GAS), motilin(MTL), D-xylose, and other related indices were detected in rats. The expression levels of TRPV1, TRPM8, and UCP1 in small intestine tissue of rats with spleen cold syndrome were detected. The results showed that eucalyptol had a certain degree of improvement in the overall state and body weight of rats with spleen cold syndrome. Compared with the spleen cold syndrome model group, high-dose eucalyptol significantly increased the levels of serum cAMP, cAMP/cGMP, TG, and TC in rats with spleen cold syndrome(P<0.05, P<0.01), decreased the content of cGMP, and significantly elevated the levels of gastrointestinal function-related indicators GAS, MTL, and D-xylose(P<0.05, P<0.01). Low-dose eucalyptol significantly increased the level of cAMP/cGMP in the serum and Na~+-K~+-ATPase levels in hepatic tissue(P<0.05, P<0.01), and significantly increased the levels of GAS and D-xylose(P<0.01). Eucalyptol showed similar effects to Atractylodis Rhizoma with a warm nature on rats with spleen cold syndrome. Compared with the spleen heat syndrome model group, the high-dose and low-dose eucalyptol groups showed a trend of increase in gastrointestinal indicators, with no significant changes in other indicators. In addition, high-dose eucalyptol increased the expression of TRPV1 and UCP1 and decreased the expression of TRPM8 in the small intestine tissue of rats with spleen cold syndrome. Eucalyptol could affect the cyclic nucleotide and material energy metabolism levels of rats with spleen cold syndrome and had a certain improvement effect on their gastrointestinal digestion and absorption function, thereby improving spleen cold syndrome. Eucalyptol had no significant improvement effect on rats with spleen heat syndrome, suggesting that eucalyptol may have a warm nature and regulate spleen meridians. It is speculated that eucalyptol may exhibit its medicinal properties by activating the TRPV1 pathway, promoting the expression of UCP1, and inhibiting the TRPM8 channel.
Animals ; Rats ; Spleen/metabolism* ; Male ; TRPV Cation Channels/genetics* ; Rats, Sprague-Dawley ; Eucalyptol/administration & dosage* ; TRPM Cation Channels/genetics* ; Uncoupling Protein 1/genetics* ; Humans ; Drugs, Chinese Herbal/administration & dosage* ; Cold Temperature ; Cyclic GMP/metabolism*

This paper aims to study the effect of p-cymene on mice with deficiency-cold syndrome induced by hydrocortisone and deficiency-heat syndrome induced by dexamethasone and explore the medicinal properties and mechanism of p-cymene with mild and warm nature based on the dominant characteristics of the two-way applicable conditions of mild drugs. A total of 80 KM mice were randomly divided into blank group, deficiency-cold syndrome model group, deficiency-cold syndrome + ginseng group, and deficiency-cold syndrome + low-dose and high-dose p-cymene groups, as well as blank group, deficiency-heat syndrome model group, deficiency-heat syndrome + American ginseng group, and deficiency-heat syndrome + low-dose and high-dose p-cymene groups. Hydrocortisone and dexamethasone solution were intragastrically administered for 14 consecutive days to prepare deficiency-cold syndrome and deficiency-heat syndrome models. Except for the blank group and the model group intragastrically administered with normal saline, the other groups were intragastrically administrated with drugs for 14 days. The levels of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), total cholesterol(TC), triglyceride(TG), immunoglobin G(IgG), and immunoglobin M(IgM) in serum, as well as the activity of Na~+-K~+-ATPase in liver tissue were detected. The expression of transient receptor potential melastatin 8(TRPM8), transient receptor potential vanilloid 1(TRPV1), and uncoupling protein 1(UCP1) in brown adipose tissue of deficiency-cold syndrome model after intervention with p-cymene was studied. The results showed that p-cymene could effectively improve the levels of cAMP, cAMP/cGMP, TC, IgM, and IgG in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and reduce the content of cGMP. The effects on T3, T4, and TG were not statistically significant. At the same time, p-cymene could reduce the levels of cAMP, cAMP/cGMP, and T4 in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and increase the levels of cGMP, IgM, and IgG, and it had no effect on T3, TC, and TG. In addition, p-cymene could up-regulate the expression of TRPV1 and UCP1 in brown fat of mice with deficiency-cold syndrome and down-regulate the expression of TRPM8. In summary, p-cymene could significantly regulate the syndrome indexes of mice with deficiency-cold syndrome, and some indexes of mice with deficiency-heat syndrome could be improved, but the effects on lipid metabolism and energy metabolism indexes were not obvious, indicating that the regulation effect of p-cymene on deficiency-cold syndrome model was more prominent and that the medicinal properties of p-cymene were mild and warm. The regulation of TRPV1/TRPM8/UCP1 channel expression may be the molecular biological mechanism of p-cymene with mild and warm nature affecting the energy metabolism of the body.
Animals ; Cymenes ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Disease Models, Animal ; Humans ; Cyclic AMP/metabolism* ; Monoterpenes/administration & dosage* ; Liver/metabolism* ; Cyclic GMP/metabolism* ; TRPV Cation Channels/genetics* ; Uncoupling Protein 1/genetics*

Emodin is a hydroxyanthraquinone compound that is widely distributed and has multiple pharmacological activities, including anti-diarrheal, anti-inflammatory, and liver-protective effects. Research indicates that emodin may be one of the main components responsible for inducing hepatotoxicity. However, studies on the mechanisms of liver injury are relatively limited, particularly those related to bile acids(BAs) metabolism. This study aims to systematically investigate the effects of different dosages of emodin on BAs metabolism, providing a basis for the safe clinical use of traditional Chinese medicine(TCM)containing emodin. First, this study evaluated the safety of repeated administration of different dosages of emodin over a 5-week period, with a particular focus on its impact on the liver. Next, the composition and content of BAs in serum and liver were analyzed. Subsequently, qRT-PCR was used to detect the mRNA expression of nuclear receptors and transporters related to BAs metabolism. The results showed that 1 g·kg~(-1) emodin induced hepatic damage, with bile duct hyperplasia as the primary pathological manifestation. It significantly increased the levels of various BAs in the serum and primary BAs(including taurine-conjugated and free BAs) in the liver. Additionally, it downregulated the mRNA expression of farnesoid X receptor(FXR), retinoid X receptor(RXR), and sodium taurocholate cotransporting polypeptide(NTCP), and upregulated the mRNA expression of cholesterol 7α-hydroxylase(CYP7A1) in the liver. Although 0.01 g·kg~(-1) and 0.03 g·kg~(-1) emodin did not induce obvious liver injury, they significantly increased the level of taurine-conjugated BAs in the liver, suggesting a potential interference with BAs homeostasis. In conclusion, 1 g·kg~(-1) emodin may promote the production of primary BAs in the liver by affecting the FXR-RXR-CYP7A1 pathway, inhibit NTCP expression, and reduce BA reabsorption in the liver, resulting in BA accumulation in the peripheral blood. This disruption of BA homeostasis leads to liver injury. Even doses of emodin close to the clinical dose can also have a certain effect on the homeostasis of BAs. Therefore, when using traditional Chinese medicine or formulas containing emodin in clinical practice, it is necessary to regularly monitor liver function indicators and closely monitor the risk of drug-induced liver injury.
Emodin/administration & dosage* ; Bile Acids and Salts/metabolism* ; Animals ; Male ; Liver/injuries* ; Chemical and Drug Induced Liver Injury/genetics* ; Drugs, Chinese Herbal/adverse effects* ; Humans ; Rats, Sprague-Dawley ; Mice ; Rats

PURPOSE: The retear rate of rotator cuff (RC) after surgery is high, and the rapid and functional enthesis regeneration remains a challenge. Whether acellular amniotic membrane (AAM) helps to promote the healing of tendon to bone and which treatment is better are both unclear. The study aims to investigate the effect of AAM on the healing of RC and the best treatment for RC repair. METHODS: Thirty-three Sprague Dawley rats underwent RC transection and repair using microsurgical techniques and were randomly divided into the suturing repair only (SRO) group (n = 11), the AAM overlaying (AOL) group (n = 11), and the AAM interposition (AIP) group (n = 11), respectively. Rats were sacrificed at 4 weeks, then examined by subsequent micro-CT, and evaluated by histologic and biomechanical tests. The statistical analyses of one-way ANOVA or Kruskal-Wallis test were performed using with SPSS 23.0. A p < 0.05 was considered a significant difference. RESULTS: AAM being intervened between tendon and bone (AIP group) or overlaid over tendon to bone junction (AOL group) in a rat model, promoted enthesis regeneration, increased new bone and cartilage generation, and improved collagen arrangement and biomechanical properties in comparison with suturing repair only (SRO group) (AOL vs. SRO, p < 0.001, p = 0.004, p = 0.003; AIP vs. SRO, p < 0.001, p < 0.001, p < 0.001). Compared with the AOL group, the AIP group had better results in micro-CT evaluation, histological score, and biomechanical testing (p = 0 0.039, p = 0.011, p = 0.003, respectively). CONCLUSION In the RC repair model, AAM enhanced regeneration of the tendon to bone junction. This regeneration was more effective when the AAM was intervened at the tendon to bone interface than overlaid above the tendon to bone junction.
Animals ; Rats, Sprague-Dawley ; Rotator Cuff Injuries/surgery* ; Amnion/transplantation* ; Rats ; Wound Healing ; Rotator Cuff/surgery* ; Male ; X-Ray Microtomography ; Tendons/surgery* ; Biomechanical Phenomena