1.Effect of elbow-wrist functional orthosis on plantar pressure and balance function in stroke patients with hemiplegia
Cheng WU ; Yunfeng ZHANG ; Weining WANG ; Kewei YU ; Yanzheng ZHANG ; Jiarong SHEN ; Yi WU
Chinese Journal of Rehabilitation Theory and Practice 2026;32(1):30-39
ObjectiveTo explore the effect of elbow-wrist functional orthosis on plantar pressure distribution and balance function in stroke patients with hemiplegia. MethodsFrom June, 2024 to April, 2025, 60 patients with post-stroke hemiplegia were recruited from Huashan Hospital, Fudan University, and Shanghai Hebin Rehabilitation Hospital. They were randomly divided into control group (n = 30) and intervention group (n = 30). The control group received routine neurological rehabilitation, while the intervention group received additional training with an elbow-wrist functional orthosis on the affected side, for eight weeks. Before and after intervention, the Modified Ashworth Scale (MAS) of the elbow joint, plantar pressure symmetry index (SI), plantar contact area and mean plantar pressure were recorded, and balance and mobility were assessed using the Berg Balance Scale (BBS), Timed Up & Go Test (TUGT) and 10-Meter Walk Test (10MWT). ResultsTwo cases dropped out in the control group. After treatment, MAS grades of the elbow joint, forefoot SI, affected side plantar pressure area, BBS scores, TUGT and 10MWT of both groups improved (|Z| > 3.969, |t| > 3.528, P < 0.01), while the hindfoot SI and average pressure of the affected foot improved in the intervention group (∣t∣ > 4.264, P < 0.001). Except for TUGT and 10MWT, the intervention group was superior to the control group (∣Z∣ > 2.030, ∣t∣ > 2.096, P < 0.05). ConclusionThe elbow-wrist functional orthosis can enhance balance function in stroke patients with hemiplegia by reducing upper-limb spasticity, optimizing center-of-gravity distribution, and improving postural control.
2.Differences in chemical components and quality analysis of Gardenia jasminoides before and after processing with ginger
Lihua TANG ; Yu WU ; Xuedi HUANG ; Xiaolian HU ; Yi TANG ; Zilong CHEN ; Xiaofan XIAO ; Xide YE
China Pharmacy 2026;37(2):168-173
OBJECTIVE To analyze the differences in chemical components of Gardenia jasminoides before and after processing with ginger, and to evaluate the quality differences among different producing areas. METHODS Ultra-high performance liquid chromatography-tandem time-of-flight mass spectrometry was used to analyze the compositional differences of G. jasminoides before and after processing with ginger. The water content, total ash, and ethanol-soluble extract content of ginger- processed G. jasminoides were determined according to the 2020 edition of Chinese Pharmacopoeia. High performance liquid chromatography was adopted to determine the contents of genipin gentiobioside, geniposide, crocin Ⅰ and crocin Ⅱ in ginger- processed G. jasminoides. RESULTS A total of 49 chemical components were identified from raw G. jasminoides and ginger- processed G. jasminoides, including 14 flavonoids, 15 iridoids, 10 organic acids, 2 alkaloids and 8 other compounds. Among them, 42 components were detected in raw G. jasminoides, 28 in ginger-processed G. jasminoides, and 21 components were common to both. After processing with ginger, raw G. jasminoides lost 21 components (including iridoids, flavonoids, alkaloids, and others), while 7 chemical components were added (including coumarins, organic acids, organic acid esters, and flavonoids). For the 15 batches of ginger-processed G. jasminoides, the water content ranged from 5.64% to 7.11%, total ash from 2.92% to 4.87%, and ethanol-soluble extract from 40.61% to 58.02%. The average contents of genipin gentiobioside, geniposide, crocin Ⅰ and crocin Ⅱ were 0.108 7, 0.542 2, 0.565 0, and 0.012 5 mg/g, respectively. CONCLUSIONS After processing with ginger, G. jasminoides loses 21 components, while 7 new components are added. Differences are observed in the water content, total ash, ethanol-soluble extract, and the contents of genipin gentiobioside, geniposide, crocin Ⅰ, and crocin Ⅱ of ginger-processed G. jasminoides from different producing areas. Notably, samples from Fujian exhibit high contents of genipin gentiobioside and ethanol-soluble extract, while samples from Jiangxi have a high content of crocin Ⅰ.
3.Effects of jaceosidin on inflammatory injury in osteoarthritis rats by regulating AMPK/NLRP3 signaling pathway
Chao WEI ; Jiang YU ; Guanyun SHENG ; Yi CAI
China Pharmacy 2025;36(4):421-426
OBJECTIVE To investigate the effects of jaceosidin on osteoarthritis (OA) of rats by regulating adenosine monophosphate-activated protein kinase (AMPK)/NOD-like receptor protein 3 (NLRP3) pathway. METHODS Rats were randomly separated into OA group, jaceosidin group (33.33 mg/kg), AMPK inhibitor (Compound C, 20 mg/kg) group, jaceosidin (33.33 mg/kg)+Compound C (20 mg/kg) group, and sham operation group, with 12 rats in each group. Except for the sham operation group, the OA model was induced with modified Hulth method in all other groups. After successful modeling, they were given a relevant dose of jaceosidin or normal saline intragastrically, and Compound C or normal saline intraperitoneally, once a day, for consecutive 8 weeks. Twenty-four h after the last medication, the degree of knee joint swelling in rats from each group was measured. The pathological changes of the articular cartilage tissue in the knee joints, and the Mankin score were assessed. The levels of tumor necrosis factor-α (TNF-α), interleukin-18 (IL-18), and IL-6, as well as the protein expressions of collagen Ⅱ, aggrecan (ACAN), and a disintegrin and metalloproteinase with thrombospondin 5 (ADAMTS5), phosphorylated AMPK (p-AMPK), AMPK, NLRP3, cleaved-caspase-1, and cleaved-IL-1β were detected in the articular cartilage tissue of rats’ knees. RESULTS Compared with OA group, the cartilage tissue defect of jaceosidin group was relieved, the cartilage matrix staining was deepened, and the number of chondrocytes was increased. Knee swelling, Mankin score, the levels of TNF- α, IL-18 and IL-6, and protein expressions of ADAMTS5, NLRP3, cleaved-caspase-1 and cleaved-IL-1β in knee cartilage were significantly decreased or down-regulated. Protein expressions of collagen Ⅱ, ACAN and phosphorylation level of AMPK were significantly increased or up-regulated (P<0.05). Compound C significantly reversed the improvement effects of jaceosidin on the above indexes of OA rats (P<0.05). CONCLUSIONS Jaceosidin may inhibit inflammation and extracellular matrix degradation in OA rats by regulating the AMPK/NLRP3 signaling pathway.
4.Construction of a system for isolation and purification of NK cells from whole blood donations
Tengyu CAO ; Huayu LIN ; Xuanzhi ZHANG ; Cuimi DUAN ; Yi LIU ; Xiaonan XUE ; Liping SUN ; Yang YU
Chinese Journal of Blood Transfusion 2025;38(2):181-188
[Objective] To explore the feasibility of using whole blood as a source of NK cells for allogeneic CAR NK cell therapy and activated NK cell reinfusion therapy, and initially construct a technical system for the separation and purification of NK cells from whole blood. [Methods] All peripheral blood mononuclear cells (PBMCs) were enriched from 400 mL of whole blood by manual separation and machine separation, respectively. The erythrocyte loss rate, PBMCs number, NK cell purity of the two methods were compared. NK cells were sorted from PBMCs by three separation and enrichment methods as immunomagnetic bead negative selection method, platelet lysate culture expansion and PERCOLL density gradient separation method, and the purity and yield of NK cells, the activity of NK cells and the tumor-killing ability of the three separation and enrichment methods were compared. [Results] The proportion of NK cells in the lymphocyte population was higher in the manual separation method than in the machine separation method[(13.16±5.16)% vs (8.56±3.92)%, P<0.05]; the number PBMCs was lower in the manual separation method than in the machine separation method[(4.09±1.80)×108vs (6.49±2.16)×108, P<0.05], and there was no difference in the red blood cell loss between the two methods (P>0.05). The purity of NK cells isolated and enriched from PBMCs by manual separation method using immunomagnetic was (96.77±2.31)%; the yield was (56.27±10.47)%; the inhibition of tumor proliferation was (38.67±14.05)%; and the tumor killing rate was (19.90±8.05)%. The purity of NK cells isolated and enriched from PBMCs by manual separation method using platelet lysis culture expansion method was the highest at day 7, which was (54.84±15.80)%; the cell expansion multiple could reach 16.92±6.28 at day 7; the in vitro tumor killing rate of NK cells was (15.83±5.5)%; the tumor inhibition rate was (44.33±13.5)%; and there was no difference in the toxicity and activity of NK cells between the two methods (P>0.05). The purity of NK cells isolated and enriched by PERCOLL density gradient separation method was (15.83±5.82)%, and the yield was (14±6.25)%, which was significantly lower than the other two methods. [Conclusion] PBMCs isolated from whole blood by manual separation and NK cells enriched by negative selection with immunomagnetic beads have the potential to provide NK cell materials for CAR-NK cell therapy, and NK cells enriched by platelet lysate-conditioned medium have the potential to provide NK cells for large-scale NK cell activation reinfusion therapy.
5.Enzyme-directed Immobilization Strategies for Biosensor Applications
Xing-Bao WANG ; Yao-Hong MA ; Yun-Long XUE ; Xiao-Zhen HUANG ; Yue SHAO ; Yi YU ; Bing-Lian WANG ; Qing-Ai LIU ; Li-He ZHANG ; Wei-Li GONG
Progress in Biochemistry and Biophysics 2025;52(2):374-394
Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.
6.Research and Application of Scalp Surface Laplacian Technique
Rui-Xin LUO ; Si-Ying GUO ; Xin-Yi LI ; Yu-He ZHAO ; Chun-Hou ZHENG ; Min-Peng XU ; Dong MING
Progress in Biochemistry and Biophysics 2025;52(2):425-438
Electroencephalogram (EEG) is a non-invasive, high temporal-resolution technique for monitoring brain activity. However, affected by the volume conduction effect, EEG has a low spatial resolution and is difficult to locate brain neuronal activity precisely. The surface Laplacian (SL) technique obtains the Laplacian EEG (LEEG) by estimating the second-order spatial derivative of the scalp potential. LEEG can reflect the radial current activity under the scalp, with positive values indicating current flow from the brain to the scalp (“source”) and negative values indicating current flow from the scalp to the brain (“sink”). It attenuates signals from volume conduction, effectively improving the spatial resolution of EEG, and is expected to contribute to breakthroughs in neural engineering. This paper provides a systematic overview of the principles and development of SL technology. Currently, there are two implementation paths for SL technology: current source density algorithms (CSD) and concentric ring electrodes (CRE). CSD performs the Laplace transform of the EEG signals acquired by conventional disc electrodes to indirectly estimate the LEEG. It can be mainly classified into local methods, global methods, and realistic Laplacian methods. The global method is the most commonly used approach in CSD, which can achieve more accurate estimation compared with the local method, and it does not require additional imaging equipment compared with the realistic Laplacian method. CRE employs new concentric ring electrodes instead of the traditional disc electrodes, and measures the LEEG directly by differential acquisition of the multi-ring signals. Depending on the structure, it can be divided into bipolar CRE, quasi-bipolar CRE, tripolar CRE, and multi-pole CRE. The tripolar CRE is widely used due to its optimal detection performance. While ensuring the quality of signal acquisition, the complexity of its preamplifier is relatively acceptable. Here, this paper introduces the study of the SL technique in resting rhythms, visual-related potentials, movement-related potentials, and sensorimotor rhythms. These studies demonstrate that SL technology can improve signal quality and enhance signal characteristics, confirming its potential applications in neuroscientific research, disease diagnosis, visual pathway detection, and brain-computer interfaces. CSD is frequently utilized in applications such as neuroscientific research and disease detection, where high-precision estimation of LEEG is required. And CRE tends to be used in brain-computer interfaces, that have stringent requirements for real-time data processing. Finally, this paper summarizes the strengths and weaknesses of SL technology and envisages its future development. SL technology boasts advantages such as reference independence, high spatial resolution, high temporal resolution, enhanced source connectivity analysis, and noise suppression. However, it also has shortcomings that can be further improved. Theoretically, simulation experiments should be conducted to investigate the theoretical characteristics of SL technology. For CSD methods, the algorithm needs to be optimized to improve the precision of LEEG estimation, reduce dependence on the number of channels, and decrease computational complexity and time consumption. For CRE methods, the electrodes need to be designed with appropriate structures and sizes, and the low-noise, high common-mode rejection ratio preamplifier should be developed. We hope that this paper can promote the in-depth research and wide application of SL technology.
7.Effect of Folic Acid-modified Crebanine Polyethylene Glycol-polylactic Acid Hydroxyacetic Acid Copolymer Nanoparticles Combined with Ultrasonic Irradiation on Subcutaneous Tumor Growth of Liver Cancer in Mice
Rui PAN ; Junze TANG ; Hailiang ZHANG ; Kun YU ; Xiaoyu ZHAO ; Xin CHENG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(4):217-225
ObjectiveTo investigate the effect of folic acid-modified crebanine polyethylene glycol-polylactic acid hydroxyacetic acid copolymer(PEG-PLGA) nanoparticles(FA-Cre@PEG-PLGA NPs, hereinafter referred to as NPs) combined with ultrasonic irradiation on subcutaneous tumor of liver cancer in Kunming(KM) mice. MethodsEighty-four healthy male KM mice were utilized to establish a subcutaneous tumor model of mouse hepatocellular carcinoma with H22 cells, then mice were randomly divided into model group, placebo group, hydroxycamptothecin group(8 mg∙kg-1), low, medium and high dose crebanine raw material groups(2, 2.5, 3 mg∙kg-1, hereinafter referred to as the low, medium and high dose crebanine groups, respectively), low, medium and high dose NPs groups(2, 2.5, 3 mg∙kg-1), and low, medium and high dose NPs combined with ultrasonic irradiation groups(2, 2.5, 3 mg∙kg-1, hereinafter referred to as the low, medium and high dose combination groups, respectively). The corresponding doses of drugs were administered via tail vein injection, the model group received no treatment, while the placebo group was injected with an equivalent amount of normal saline. Dosing was conducted for a total of 10 times on alternate days. The body mass of the mice was monitored, and parameters such as body mass change rate, thymus index, spleen index, tumor volume, tumor weight, relative tumor growth rate(T/C), and tumor inhibition rate(TGI) were calculated. Pathological changes in liver and kidney tissues as well as the tumor were observed by hematoxylin-eosin(HE) staining. Additionally, the levels of aspartate aminotransferase(AST), alanine aminotransferase(ALT), blood urea nitrogen(BUN) and creatinine(CREA) in serum of mice were detected by biochemical method. Furthermore, the effect of ultrasound on the distribution of NPs in subcutaneous tumors of mouse hepatocellular carcinoma was observed by in vivo imaging technique. ResultsAmong different treatment methods, the combination of NPs and ultrasound irradiation had the best therapeutic effect. Compared with the model group, the body mass growth rates of mice in the medium and high combination groups decreased, while the thymus index and spleen index increased, but there was no statistically significant difference in serum AST, ALT, BUN and CREA levels, indicating that NPs combined with ultrasound irradiation had little effect on the normal physiological state of the body, oth groups had TGI>40% and T/C<60%, indicating a clear anti-tumor effect. Pathological analysis showed that compared with the NPs groups, the combination groups exhibited varying degrees of necrosis in tumor cells, accompanied by less damage to the liver and kidneys. In vivo imaging of small animals showed that compared with the high dose NPs group, the high dose combination group had stronger tumor targeting ability(P<0.01). ConclusionNPs combined with ultrasonic irradiation can not only effectively targeted the drug to the tumor site, inhibit the subcutaneous tumor growth of mouse liver cancer, but also decrease damage to liver and kidney tissues.
8.Outcomes of identifying enlarged vestibular aqueduct (Mondini malformation) related gene mutation in Mongolian people
Jargalkhuu E ; Tserendulam B ; Maralgoo J ; Zaya M ; Enkhtuya B ; Ulzii B ; Ynjinlhkam E ; Chuluun-Erdene Ts ; Chen-Chi Wu ; Cheng-Yu Tsai ; Yin-Hung Lin ; Yi-Hsin Lin ; Yen-Hui Chan ; Chuan-Jen Hsu ; Wei-Chung Hsu ; Pei-Lung Chen
Mongolian Journal of Health Sciences 2025;87(3):8-15
Background:
Hearing loss (HL) is one of the most common sensory disorders,
affecting over 5-8% of the world's population. Approximately half of HL cases are
attributed to genetic factors. In hereditary deafness, about 75-80% is inherited
through autosomal recessive inheritance, and common pathogenic genes include
GJB2 and SLC26A4. Pathogenic variants in the SLC26A4gene are the leading
cause of hereditary hearing loss in humans, second only to the GJB2 gene. Variants in the SLC26A4gene cause hearing loss, which can be non-syndromic autosomal recessive deafness (DFNB4, OMIM #600791) associated with enlarged
vestibular aqueduct (EVA) or Pendred syndrome (Pendred, OMIM #605646).
DFNB4 is characterized by sensorineural hearing loss combined with EVA or less
common cochlear malformation defect. Pendred syndrome is characterized by bilateral sensorineural hearing loss with EVA and an iodine defect that can lead to
thyroid goiter. Currently, it is known that EVA is associated with variants in the
SLC26A4 gene and is a penetrant feature of SLC26A4-related HL. Predominant
mutations in these genes differ significantly across populations. For instance, predominant SLC26A4 mutations differ among populations, including p.T416P and
c.1001G>A in Caucasians, p.H723R in Japanese and Koreans, and c.919-2A>G
in Han Taiwanese and Han Chinese. On the other hand, there has been no study
of hearing loss related to SLC26A4 gene variants among Mongolians, which is the
basis of our research.
Aim:
We aimed to identify the characteristics of the SLC26A4 gene variants in
Mongolian people with Enlarged vestibular aqueduct and Mondini malformation.
Materials and Methods:
In 2022-2024, We included 13 people with hearing loss
and enlarged vestibular aqueduct, incomplete cochlea (1.5 turns of the cochlea
with cystic apex- incomplete partition type II- Mondini malformation) were examined by CT scan of the temporal bone in our study. WES (Whole exome sequencing) analysis was performed in the Genetics genetic-laboratory of the National
Taiwan University Hospital.
Results:
Genetic analysis revealed 26 confirmed pathogenic variants of bi-allelic
SLC26A4 gene of 8 different types in 13 cases, and c.919-2A>G variant was dominant with 46% (12/26) in allele frequency, and c.2027T>A (p.L676Q) variant 19%
(5/26), c.1318A>T(p.K440X) variant 11% (3/26), c.1229C>T (p.T410M) variant 8%
(2/26) ) , c.716T>A (p.V239D), c.281C>T (p.T94I), c.1546dupC, and c.1975G>C
(p.V659L) variants were each 4% (1/26)- revealed. Two male children, 11 years
old (SLC26A4: c.919-2A>G) and 7 years old (SLC26A4: c.919-2A>G:, SLC26A4:
c.2027T>A (p.L676Q))had history of born normal hearing and progressive hearing
loss.
Conclusions
1. 26 variants of bi-allelic SLC26A4 gene mutation were detected
in Mongolian people with EVA and Mondini malformation, and c.919-2A>G was
the most dominant allele variant, and rare variants such as c.1546dupC, c.716T>A
(p.V239D) were detected.
2. Our study shows that whole-exome sequencing (WES) can identify gene
mutations that are not detected by polymerase chain reaction (PCR) or NGS analysis.
9.Application of Engineered Exosomes in Tumor-targeted Therapy
Jia-Lu SONG ; Yi-Xin JIN ; Xing-Yu MU ; Yu-Huan JIANG ; Jing WANG
Progress in Biochemistry and Biophysics 2025;52(5):1140-1151
Tumors are the second leading cause of death worldwide. Exosomes are a type of extracellular vesicle secreted from multivesicular bodies, with particle sizes ranging from 40 to 160 nm. They regulate the tumor microenvironment, proliferation, and progression by transporting proteins, nucleic acids, and other biomolecules. Compared with other drug delivery systems, exosomes derived from different cells possess unique cellular tropism, enabling them to selectively target specific tissues and organs. This homing ability allows them to cross biological barriers that are otherwise difficult for conventional drug delivery systems to penetrate. Due to their biocompatibility and unique biological properties, exosomes can serve as drug delivery systems capable of loading various anti-tumor drugs. They can traverse biological barriers, evade immune responses, and specifically target tumor tissues, making them ideal carriers for anti-tumor therapeutics. This article systematically summarizes the methods for exosome isolation, including ultracentrifugation, ultrafiltration, size-exclusion chromatography (SEC), immunoaffinity capture, and microfluidics. However, these methods have certain limitations. A combination of multiple isolation techniques can improve isolation efficiency. For instance, combining ultrafiltration with SEC can achieve both high purity and high yield while reducing processing time. Exosome drug loading methods can be classified into post-loading and pre-loading approaches. Pre-loading is further categorized into active and passive loading. Active loading methods, including electroporation, sonication, extrusion, and freeze-thaw cycles, involve physical or chemical disruption of the exosome membrane to facilitate drug encapsulation. Passive loading relies on drug concentration gradients or hydrophobic interactions between drugs and exosomes for encapsulation. Pre-loading strategies also include genetic engineering and co-incubation methods. Additionally, we review approaches to enhance the targeting, retention, and permeability of exosomes. Genetic engineering and chemical modifications can improve their tumor-targeting capabilities. Magnetic fields can also be employed to promote the accumulation of exosomes at tumor sites. Retention time can be prolonged by inhibiting monocyte-mediated clearance or by combining exosomes with hydrogels. Engineered exosomes can also reshape the tumor microenvironment to enhance permeability. This review further discusses the current applications of exosomes in delivering various anti-tumor drugs. Specifically, exosomes can encapsulate chemotherapeutic agents such as paclitaxel to reduce side effects and increase drug concentration within tumor tissues. For instance, exosomes loaded with doxorubicin can mitigate cardiotoxicity and minimize adverse effects on healthy tissues. Furthermore, exosomes can encapsulate proteins to enhance protein stability and bioavailability or carry immunogenic cell death inducers for tumor vaccines. In addition to these applications, exosomes can deliver nucleic acids such as siRNA and miRNA to regulate gene expression, inhibit tumor proliferation, and suppress invasion. Beyond their therapeutic applications, exosomes also serve as tumor biomarkers for early cancer diagnosis. The detection of exosomal miRNA can improve the sensitivity and specificity of diagnosing prostate and pancreatic cancers. Despite their promising potential as drug delivery systems, challenges remain in the standardization and large-scale production of exosomes. This article explores the future development of engineered exosomes for targeted tumor therapy. Plant-derived exosomes hold potential due to their superior biocompatibility, lower toxicity, and abundant availability. Furthermore, the integration of exosomes with artificial intelligence may offer novel applications in diagnostics, therapeutics, and personalized medicine.
10.Effect of The Hydrophilic Amino Acids on Self-assembly Behavior of Short Bola-like Peptides
Xin-Xin GAO ; Yu HAN ; Yi-Lin ZHOU ; Xi-Ya CHEN ; Yu-Rong ZHAO
Progress in Biochemistry and Biophysics 2025;52(5):1290-1301
ObjectiveBola-like short peptides exhibit novel self-assembly properties due to the formation of peptide dimers via hydrogen bonding interactions between their C-terminals. In this configuration, hydrophilic amino acids are distributed at both terminals, making these peptides behave similarly to Bola peptides. The electrostatic repulsive interactions arising from the hydrophilic amino acids at each terminal can be neutralized, thereby greatly promoting the lateral association of β-sheets. Consequently, assemblies with significantly larger widths are typically the dominant nanostructures for Bola-like peptides. To investigate the effect of hydrophilic amino acids on the self-assembly behavior of Bola-like peptides, the peptides Ac-RI3-CONH2 and Ac-HI3-CONH2 were designed and synthesized using the Bola-like peptide Ac-KI3-CONH2 as a template. Their self-assembly behavior was systematically examined. MethodsAtomic force microscopy (AFM) and transmission electron microscopy (TEM) were employed to characterize the morphology and size of the assemblies. The secondary structures of the assemblies were analyzed using circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy. Small-angle neutron scattering (SANS) was used to obtain detailed structural information at a short-length scale. Based on these experimental results, the effects of hydrophilic amino acids on the self-assembly behavior of Bola-like short peptides were systematically analyzed, and the underlying formation mechanism was explored. ResultsThe aggregation process primarily involved three steps. First, peptide dimers were formed through hydrogen bonding interactions between their C-terminals. Within these dimers, the hydrophilic amino acids K, R, and H were positioned at both terminals, enabling the peptides to self-assemble in a manner similar to Bola peptides. Next, β-sheets were formed via hydrogen bonding interactions along the peptide backbone. Finally, self-assemblies were generated through the lateral association of β-sheets. The results demonstrated that both Ac-KI3-CONH2 and Ac-RI3-CONH2 could self-assemble into double-layer nanotubes with diameters of approximately 200 nm. These nanotubes were formed by the edge fusion of helical ribbons, which initially emerged from twisted ribbons. Notably, the primary assemblies of these peptides exhibited opposite chirality: nanofibers formed by Ac-KI3-CONH2 displayed left-handed chirality, whereas those formed by Ac-RI3-CONH2 exhibited right-handed chirality. This reversal in torsional direction was primarily attributed to the different abilities of K and R to form hydrogen bonds with water. In contrast, Ac-HI3-CONH2 formed narrower twisted ribbons with a significantly reduced width of approximately 30 nm, which was attributed to the strong steric hindrance caused by the imidazole rings. The multilayer height of these ribbons was mainly due to the unique structure of the imidazole rings, which can function as both hydrogen bond donors and acceptors, thereby promoting aggregate growth in the vertical direction. ConclusionThe final morphology of the self-assemblies resulted from a delicate balance of various non-covalent interactions. By altering the types of hydrophilic amino acid residues in Bola-like short peptides, the relative strength of non-covalent interactions that drive assembly formation can be effectively regulated, allowing precise control over the morphology and chirality of the assemblies. This study provides a simple and effective approach for constructing diverse self-assemblies and lays a theoretical foundation for the development of functional biomaterials.

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