Research progress on the role of cytochrome P450 in plant sesquiterpene biosynthesis / 药学学报

Sesquiterpenes are natural terpenoids with 15 carbon atoms in the basic skeleton, which mainly exist in plant volatile oil and have important physiological and medicinal value. Cytochrome P450 (CYP450) is a kind of monooxygenase encoded by supergene family, which is one of the largest gene families in plants. It is involved in the synthesis and metabolism of terpenoids, alkaloids and other secondary metabolites. In the process of terpene biosynthesis, CYP450 participates in the post-modification stage of terpenes by introducing functional groups such as hydroxyl, carboxyl and carbonyl, which plays an important role in enriching the diversity of terpenes. The CYP450 enzymes involved in sesquiterpene synthesis and their substrate catalytic specificity mechanisms have been partially investigated. In this paper, the biosynthetic pathway of plant sesquiterpenes, the structure and classification of CYP450 enzymes were briefly introduced, and the CYP450 enzymes involved in sesquiterpene biosynthesis were summarized, in order to provide a reference for intensive study of the role of CYP450 enzymes in the synthesis of sesquiterpenoids.

Anxiolytic and antidepressant effects of agarwood inhalation and its mechanism / 中国中药杂志

This study used m-chloropheniperazine(MCPP) and chronic unforeseeable mild stress(CUMS) to induce the rat models of anxiety and depression, respectively. The behaviors of rats were observed by the open field test(OFT), light-dark exploration test(LDE), tail suspension test(TST), and forced swimming test(FST), and the antidepressant and anxiolytic effects of agarwood essential oil(AEO), agarwood fragrant powder(AFP), and agarwood line incense(ALI) were explored. The enzyme-linked immunosorbent assay(ELISA) was used to determine the levels of 5-hydroxytryptamine(5-HT), glutamic acid(Glu), and γ-aminobutyric acid(GABA_A) in the hippocampal area. The Western blot assay was used to determine the protein expression levels of glutamate receptor 1(GluR1) and vesicular glutamate transporter type 1(VGluT1), exploring the anxiolytic and antidepressant mechanism of agarwood inhalation. The results showed that compared with the anxiety model group, the AEO, AFP, and ALI groups decreased the total distance(P<0.05), decreased the velocity of movements(P<0.05), prolonged the immobile time(P<0.05), and reduced the distance and velocity of the rat model of anxiety in the dark box(P<0.05). Compared with the depression model group, the AEO, AFP, and ALI groups increased the total distance and average velocity(P<0.05), reduced the immobile time(P<0.05), and reduced the forced swimming and tail suspension time(P<0.05). In terms of transmitter regulation, the AEO, AFP, and ALI groups decreased the level of Glu in the rat model of anxiety(P<0.05) and increased the levels of GABA_A and 5-HT(P<0.05), while the AEO, AFP, and ALI groups all increased the level of 5-HT in the rat model of depression(P<0.05) and decreased the levels of GABA_A and Glu(P<0.05). At the same time, the AEO, AFP, and ALI groups all increased the protein expression levels of GluR1 and VGluT1 in the hippocampus of the rat models of anxiety and depression(P<0.05). In conclusion, AEO, AFP, and ALI exert anxiolytic and antidepressant effects, and the mechanism might be related to the regulation of the neurotransmitter and the protein expression of GluR1 and VGluT1 in the hippocampus.

Two new sesquiterpenes in Qi-nan Aquilariae Lignum Resinatum / 中国中药杂志

This study aimed to investigate the chemical constituents of supercritical extract from Qi-nan Aquilariae Lignum Resinatum by silica gel column chromatography, thin-layer chromatography, and semi-preparative high-performance liquid chromatography. One new elemane-type and one new eudesmane-type sesquiterpene compounds were isolated from the extract, and their structures were identified by MS, UV, IR, NMR, and ECD spectroscopic techniques, and named aquqinanol C(1) and aquqinanol D(2). Both compounds are novel compounds. The neuroprotective effect of the compounds on CORT-induced PC12 cell damage was determined in vitro. The results showed that compounds 1 and 2 exhibited a certain protective effect against CORT-induced damage in PC12 cells.

Cloning and expression analysis of cytochrome P450 AsCYP71D1 from Aquilaria sinensis (Lour.) Gilg / 药学学报

Cytochrome P450 (CYP450) is a kind of superfamily oxidase containing heme, which is distributed in various aerobic organisms. They are widely involved in the biosynthesis of terpenoids, alkaloids, flavonoids, fatty acids, etc. In this study, the full-length cDNA sequence of a P450 was cloned by reverse transcription-PCR (RT-PCR) and rapid amplification of cDNA ends (RACE) technology, with the specific primers that designed according to the sequence of a transcript annotated as P450 from the Aquilaria sinensis (Lour.) Gilg transcriptome database. The tissue expression and subcellular localization were also studied. The full-length cDNA of the cloned P450 gene is 1 920 bp, with 88 bp 5′-untranslated region (UTR), 344 bp 3′-UTR and a 21 bp polyA tail, and 1 488 bp open reading frame (ORF), encoding 495 amino acids. Sequence alignment revealed that the protein belonged to CYP71D family of cytochrome P450 family, and named AsCYP71D1. Tissue expression analysis indicated that AsCYP71D1 was mainly expressed in stem. Further subcellular localization of onion epidermis showed that AsCYP71D1 was expressed in cytoplasm, nucleus and cell membrane. This study will provide a foundation for further research on its function in agarwood sesquiterpene biosynthesis.

Analysis and suggestions on harvest period standards of plant medicinal materials in 2020 edition of Chinese Pharmacopoeia / 中国中药杂志

The improvement of the harvest period standards is critical in the quality control of Chinese medicinal materials. The present study statistically analyzed the harvest period standards of plant medicinal materials in the 2020 edition of Chinese Pharmacopoeia(Vol.Ⅰ) and put forward the existing problems and suggestions based on herbal records and modern research to provide references for the improvement of the standards. According to the statistical analysis, in 499 types of plant medicinal materials, harvest period standards are recorded under 486 types, accounting for 97.4%, and are lacking in the remaining. Only one medicinal material(Stellariae Radix) is recorded with the standard of the harvest year. The standards of the harvest season and phenological period are recorded under 233 types, accounting for 46.7%. For 237 types, only harvest season is specified, accounting for 47.5%, and for 15 types, only harvest phenological period is specified, accounting for 3.0%. Among 222 types mainly derived from cultivation and 51 types from wild resources and cultivation, only 11 types are recorded with harvest period of cultivated products. Only Stellariae Radix is recorded with the harvest period standards for the wild and cultivated products separately. The harvest period standards of plant medicinal materials with different medicinal parts have certain rules to follow. The main problems about the harvest period standards are discovered. Specifically, no harvest period standards are recorded under 13 types of plant medicinal materials. Almost all perennial cultivated medicinal materials are not recorded with harvest year standard. No phenological period standard is found under 250 types of plant medicinal materials. There is no clear distinction between the harvest period standards of cultivated and wild products. The evidence for harvest period standards of 26 types of plant medicinal materials that can be harvested all year round is insufficient. As a result, it is proposed to strengthen basic research in response to the above-mentioned problems and improve the harvest period standards as soon as possible to ensure the quality of Chinese medicinal materials.

Anti-asthmatic effect of agarwood alcohol extract in mice and its mechanism / 中国中药杂志

As recorded, agarwood has the function of improving qi reception and relieving asthma, but the underlying mechanism is unclear and rarely reported. Therefore, this study explored the anti-asthmatic effect of the alcohol extract of agarwood produced by the whole-tree agarwood-inducing technique(Agar-Wit) in the asthma mouse model induced by intraperitoneal injection of ovalbumin(OVA) + Al(OH)_3 combined with intranasal administration of OVA and the mechanism, and compared the anti-asthmatic effects of agarwood induced with different methods. Firstly, the anti-inflammatory and anti-asthmatic effects of Agar-Wit agarwood in mice were evaluated based on the asthma frequency, lung tissue injury, and peripheral inflammatory white blood cell(WBC) count and eosinophil count. Then, the levels of interleukin-1β(IL-1β), IL-17, and IL-10 in serum of mice were detected by enzyme-linked immunoassay(ELISA) and the expression of inflammation-and apoptosis-related genes in tissues was measured by reverse transcription polyme-rase chain reaction(RT-PCR) so as to preliminarily explore the anti-asthmatic mechanism. RESULTS:: showed that the alcohol extract of Agar-Wit agarwood significantly reduced asthma frequency, relieved pathological injury, improved peripheral WBC count and eosinophil count, decreased the levels of inflammatory cytokines IL-1β and IL-17, elevated the level of anti-inflammatory cytokine IL-10, and down-regulated the mRNA expression of IL-1 R, tumor necrosis factor receptor R(TNFR), nuclear transcription factor-kappa B(NF-κB), Bax, and caspase 3, but had no significant influence on the expression of high-mobility group box 1(HMGB1) protein, caspase 8, and Bcl-2. The effect of Agar-Wit agarwood alcohol extract was better than that of wild agarwood alcohol extract and alcohol extract of agarwood induced with the burning-chisel-drilling method at the same dose. In conclusion, Agar-Wit agarwood can significantly alleviate inflammation and asthma, which is related to its anti-inflammation and anti-apoptosis activity.

Anti-inflammatory sesquiterpenes from agarwood produced via whole-tree agarwood-inducing technique of Aquilaria sinensis / 中国中药杂志

The present study is to investigate the chemical constituents and anti-inflammation of agarwood produced via whole-tree agarwood-inducing technique( Agar-Wit) from Aquilaria sinensis by column chromatographic technique and semi-preparation HPLC.Eleven sesquiterpenes were isolated from the agarwood produced by Agar-Wit,and their structures were identified on the basis of physiochemical characteristics and spectroscopic data analysis as baimuxinol( 1),5α,7α( H)-eudesm-11( 13)-en-4α-ol( 2),( 7 S,9 S,10 S)-( +)-9-hydroxy-selina-4,11-dien-14-al( 3),petafolia A( 4),7( 11)-eremophilen-8-one( 5),neopetasane( 6),petafolia B( 7),11-hydroxy-valenc-1( 10)-en-2-one( 8),( 4αβ,7β,8αβ)-3,4,4α,5,6,7,8,8α-octahydro-7-[1-( hydroxymethyl) ethenyl]-4α-methylnaphthalene-1-carboxaldehyde( 9),12-hydroxy-4( 5),11( 13)-eudesmadien-15-al( 10),and( 4 R,5 R,7 S,9 S,10 S)-(-)-eudesma-11( 13)-en-4,9-diol( 11). Among them,compound 1 was a new natural product,and this is the first time to report its13 CNMR spectroscopic data. Compounds 4,9 and 10 were reported from Aquilaria for the first time,and all the compounds are firstly isolated by Agar-Wit from A. sinensis. The anti-inflammatory activity of RAW264. 7 cells with lipopolysaccharide-induced was evaluated.As a result,1,4 and 9 showed potential anti-inflammatory activities with IC50 values( 2. 5±0. 35),( 3. 2±0. 2),( 4. 3±0. 56) μmol·L-1,respectively. This work provided scientific foundation for quality evaluation of the agarwood produced by Agar-Wit.

Genome survey analysis and SSR loci mining of Bupleurum falcatum / 中国中药杂志

Buplewrum falcatum is a traditional Chinese medicine,which is mainly used for the treatment of cold and liver protection. B. falcatum is dominantly cultivated in Japan as well as planted in China,Korea and other countries and regions. In order to determine the appropriate sequencing strategy,the genome survey before large-scale genome sequencing is needed. This survey can provide information about the size and complexity of the whole genome of the target species. In the present study,the next generation sequencing technology( Illumina Hiseq 2000) was used to analyze the genome size and complexity of B. falcatum. In addition,SSR loci were analyzed from the sequenced data. Primer 3 was used to design specific primers and 33 pairs of primers were randomly selected for PCR with template DNA of B. falcatum,and the PCR system and optimal annealing temperature were screened. A total of 288. 64 G genome sequence data was obtained,and the estimated genome size of B. falcatum was 2 119. 58 Mb. The measured genome data depth was138×; the rate of heterozygosity was 1. 84%; and the ratio of repeat sequence was 83. 89%. It is speculated that the genome of B. falcatum is complex. The preliminary assembly was performed with K-mer = 41,and the contig N50 was 224 bp,the total length 896. 97 Mb,the scaffold N50 313 bp,and the total length was 922. 67 Mb. A total of 91 377 SSR sequences were detected in the sequenced genome data which were distributed in 70 809 unigenes.The main type is dinucleotide repeats,with 49 680 sequences,accounting for70. 16%. Among the 33 pairs of primers randomly synthesized according to the obtained SSR sequences,21 pairs were successfully amplifying the target sequences. The results will be helpful for later large scale genome sequencing and SSR molecular markers development for germplasm identification and trait mapping.

Research of pollution-free and precision cultivation system of Chinese herbal medicines / 中国中药杂志

The issues of disordering production and non-standard pesticide application are common in the production of Chinese herbal medicines. Aimed to above problems, research groups built the pollution-free and precision cultivation system of medicinal plants. This system mainly included the precise site selection of medicinal plants based on the GIS technology, modern omics-assisted breeding, metagenomics guiding the soil complex improvement, and the precise field management based on rational application of fertilizer and comprehensive control of disease. At present, the production and distribution of medicinal plants were performed in the many poor counties of the whole nation. The breeding platform of resistant varieties was built, and certificates of new and well-bred varieties were received, in the base of genetic backgrounds of the original species of medicinal plants. The disease incidences were declined after application of these resistant varieties. Additionally, chemical pesticide consumption of medicinal plants (such as Panax ginseng, P. notoginseng, Salvia miltiorrhiza, P. quinquefolium, Schisandra chinensis, Platycodon grandiflorum and P. grandiflorus etc.) reduced by 20%-80% based on the genetic testing technologies of plant diseases and insect pests and safety evaluation of pollution-free pesticides. The application of pollution-free and precision cultivation system of Chinese herbal medicines achieve significantly social, economic and ecological benefits.

Advances in study of plant type Ⅲ polyketide synthases / 中国中药杂志

Polyketides are a large class of natural products with notable structural diversity and different biological activities. They have essential pharmacological value for human health. In plants, the enzymes responsible for the formation of phenolic metabolites backbone structures are collectively known as type Ⅲ polyketide synthases (PKSs), which are the key enzymes for the polyketides biosynthesis. The PKSs catalyze a series of condensation reactions of two-carbon acetate units with an acyl starter. A brief overview of this group of enzymes, including their reaction mechanisms, function modification, expression regulation, molecular evolution, and recent interesting findings are presented here.

Viability of 7 kinds of medicinal plant seeds stored in medium-term gene bank of the National Medicinal Plant Gene Bank / 中国中药杂志

In order to evaluate seed viability of Platycodon grandiflorum, Schizonepeta tenuifolia, Andrographis paniculat, Codonopsis pilosula, Scutellaria baicalensis, Leonurus japonicus, Rabdosia rubescens, stored in the medium-term gene bank of the National Medicinal Plant Gene Bank for 4 years, we tested seed germination rate of 7 species of medicinal plant and analyzed the change of significance of levels of the germination rate in pre and post store. Seed germination rates of 7 species of medicinal plants were all decreased after 4 years, and the decrease of S. tenuifolia and S. baicalensis germination rates were much smaller than other species. The higher initial germination rate of P. grandiflorum, C. pilosula, R. rubescens seed has the smaller decline of germination rate, but the data of A. paniculata showed the opposite trend. The rate decline of the germination of S. tenuifolia and S. baicalensis was roughly the same in different germination rate interval. The results showed that low temperature storage could effectively prolong the seed longevity, and maintain the seed vigor. Moreover, it is necessary to study on the storage characteristics of the main medicinal plant seeds, and establish the monitoring plan and regeneration standard.

Evaluation of efficiency of traps baited with frequency trembler grid lamps and trap plants for control Heortia vitessoides infectwed in Aquilaria sinensis / 中国中药杂志

Heortia vitessoides has been a serious defoliating pest of Aquilaria sinensis forests in recent years.The adults displayed strong tropism to the frequency trembler grid lamps and the nectar source plants.The favorite nectar source plants of H.vitessoides adults as the trap plants and the frequency trembler grid lamps in the integrated management of H.vitessoides were studied in the adult eclosion period through both the laboratory and field.The results showed that Kuhnia rosmarnifolia and Santalum album plants showed strong attraction to the H.vitessoides adults, with significant differences among the different nectar source plants.K.rosmarnifolia and S.album as trap plants with board type of planting area to total planting area of 5%-10%, and the frequency trembler grid lamps trapped significantly more adults of H.vitessoides. These results suggested that the frequency trembler grid lamps and trap plants could play an important role in the integrated management of the pest H.vitessoides of A.sinensis.

Construction and expression of prokaryotic vector of AsJAZ1 gene from Aquilaria sinensis / 中国中药杂志

The full-length coding sequence (cds) of jasmonate-zim-domain protein (AsJAZ1) gene was cloned from Aquilaria sinensis, the prokaryotic vector was constructed and the recombinant proteins expression was induced to provide the basic material for interactive proteins screen and gene function research. In this study, with the total RNA isolated from A. sinensis leave as template, the full-length cds of AsJAZ1 gene was amplified using RT-PCR method and subcloned into pET-28a vector. The recombinant plasmid identified by restriction enzyme digestion and nucleotide sequencing was transformed into E. coli BL21(DE3). Inducing with 0.5 mmol•L⁻¹ IPTG at 37 ℃ for 4 hours, a fusion protein about 39 kDa was maximumly obtained. AsJAZ1 fusion protein had been expressed successfully mainly in the form of inclusion bodies and only a very small amount was secreted into the cytoplasm in the supernatant.

Prokaryotic expression and purification of Aquilaria sinensis (Lour.) Gilg AsMYC2 protein / 药学学报

The MYC2 transcription factor is a member of the important plant bHLH transcription factor families, and it is also the core regulatory elements in jasmonate (JA) signaling pathway. However, there is a little information about AsMYC2 gene in Aquilaria sinensis. In this study, with the total RNA isolated from A. sinensis leave as template, the full-length coding sequence (CDS) of AsMYC2 gene was amplified using RT-PCR method and subcloned into pGEX-4T-1 vector by the gene recombination technique. The recombinant vector pGEX-4T-1-AsMYC2 was verified by restriction enzyme digestion and nucleotide sequencing, and was transformed into E. coli BL21(DE3) to express the protein. A maximum expression of soluble protein was observed with induction by 0.1 mmol·L-1 IPTG at 37℃ for 4 hours. The fusion protein was purified through a Sepharose-Glutathione column, and verified by SDS-PAGE and Western blotting using an anti-GST polyclonal antibody. We successfully constructed the GST-AsMYC2 plasmid, produced and purified the GST-AsMYC2 fusion protein, which would provide the basic material for polyclonal antibody preparation, interactive factors screening and gene function research. According to the tissue-specific expression pattern analysis by qRT-PCR method, the AsMYC2 gene in A. sinensis tissues is mainly expressed in roots and stems, the main agarwood formation parts, and lowest expressed in leaves. These results indicate that AsMYC2 gene likely play some roles in agarwood formation in A. sinensis.

Establishment of traceability system of Chinese medicinal materials' quality / 中国中药杂志

The quality of Chinese medicinal materials relates greatly to the clinical curative effect and security. In order to ensure the quality and safety of Chinese medicinal materials, a systematic and operable traceability system needs to be established. It can realize the whole process of quality and safety management of Chinese medicinal materials "from production to consumption" through recording and inquiring information and recalling defective products, which is an important direction for the future development of traditional Chinese medicine. But it is still at the exploration and trial stage. In this paper, a framework of Chinese medicinal materials' quality and safety traceability system was established on the basis of the domestic and international experience about the construction of food and agricultural products traceability systems. The relationship between traceability system of Chinese medicinal materials' quality and GAP, GMP, GSP was analyzed, and the possible problems and the corresponding solutions were discussed.

Establishment of a cell suspension culture system of endangered Aquilaria sinensis (Lour.) Gilg / 药学学报

Aquilaria sinensis callus induced by stem tips were used to establish the suspension cell system. The results showed that the most suitable medium for callus induction and subculture is MS + 2.0 mg x L(-1) NAA + 1.0 mg x L(-1) 6-BA. After 12 times of subculture, the energetic and loose callus, which were appropriate for cell suspension culture, were cultured and shook in liquid medium MS + 2.0 mg x L(-1) NAA + 1.0 mg x L(-1) 6-BA + 500.0 mg x L(-1) casein hydrolysate (CH) to establish the suspension cell system. The growth curve of suspension cells showed a "S" type. At the beginning of the culture, cell density increased slowly; during 4 to 6 days, suspension cells reached logarithmic growth period; during 7 to 12 days, suspension cells were in the platform period; but after 12 days, cell density and activity went down obviously. Agarwood sesquiterpenes were not detected in the suspension cells during the growth period, however, they could be detected in MeJA treated suspension cells. In this study, a stable and active growing suspension cell system was established, which was a proper system to study the mechanism of agarwood sesquiterpene formation, and additionally provided a potential way to generate agarwood sesquiterpenes through application of cell culture.

Cryopreservation study on seeds and embryos in Dalbergia odorifera / 中国中药杂志

The mature seeds and excised embryos of Dalbergia odorifera were used as materials to study the effect of moisture content on their survival, as well as the effect of rapid freezing and vitrification freezing method on seeds and in vitro embryos cryopreservation. The results showed that the germination rate and vigor decreased from 82.67%, 85% to 18.35%, 25% respectively, when the seed moisture content decreased from 15.04% to 8.14%; and the germination rate decreased from 82.67% to 37.50%, 25.37% respectively by vitrification freezing method and rapid freezing method, when the seed moisture content decreased from 15.04% to 9.37%. Among all the moisture content gradient, 12.35% moisture reached the maximal germination rate, which were 63.58% and 50.45% respectively by vitrification freezing and rapid freezing; and when the embryo moisture content was 26.32%, the germination rate decreased from 95.67% to 58.31% and 33.82% respectively by vitrification freezing and rapid freezing. And when the moisture content was in the range of 14.17% -21.34%, the germination rate was a bit of decrease. The experiment results showed that the optimum conditions of seed cryopreservation were: moisture content 12.35%, vitrification freezing; and the optimum conditions of in vitro embryo cryopreservation were: moisture 15.04%, vitrification freezing. In conclusion, the effects of moisture content on germination rate after cryopreservation in D. odorifera seeds and embryo were significant, and vitrification freezing method is much better than rapid freezing method.

Cloning and gene expression of acetyl-CoA C-acetyl transferase gene (AsAACT) from Aquilaria sinensis / 中国中药杂志

<p><b>OBJECTIVE</b>This study aimed to clone the acetyl-CoA C-acetyl transferase (AACT) gene from Aquilaria sinensis and analyze the bioinformatics and expression of the gene.</p><p><b>METHOD</b>One unique sequence containing partly AACT gene sequence was discovered in our previous transcriptome dataset of A. sinensis. AACT gene was cloned by RT-PCR and RACE strategy with the template of RNA extracted from A. sinensis stem. The bioinformatic analysis of this gene and its corresponding protein was performed. The AsAACT expression in calli was analyzed with GADPH gene as an internal control gene in wounded condition by qRT-PCR technique.</p><p><b>RESULT</b>One unique sequence of AACT, named as AsAACT, was cloned from A. sinensis. The full length of AsAACT cDNA was containing a 1 236 bp ORF that encoded 411 amino acids. The result of qRT-PCR displayed that the highest expression level was at 4 h. which indicated that it was possibly involved in early-stage response to wound.</p><p><b>CONCLUSION</b>Cloning and analyzing AsAACT gene from A. sinensis provided basic information for study the function and expression regulation of AsAACT in terpenoid biosynthesis.</p>

Expression analyses of BcUGT3 and BcUGT6, and their in vitro expression in Escherichia coli / 中国中药杂志

The tissue-specific and MeJA-induced transcriptional levels of BcUGT3 and BcUGT6 in Bupleurum chinense were analyzed in the present study. The transcriptional levels of BcUGT3 in root, leaf, flower and fruit were similar and they all were higher than those in stem. The transcriptional level of BcUGT6 was the highest in leaf and the lowest in flower among in all tested tissues. With non-treated adventitious roots as control, BcUGT6's transcriptional levels were elevated to nearly 2 folds for 2 h, 8 h, 24 h, 2 d and 4 d in MeJA-treated adventitious roots of B. chinense. It showed that the transcriptional level of BcUGT6 was slightly affected by MeJA. While, BcUGT3's transcriptional levels were gradually elevated, and till 4 d after MeJA treatment, the expression level was about 7 folds than that of non-treated control. Using pET-28a (+), the expressions of two genes was investigated. Induced by IPTG, the target proteins were expressed in E. coli and then purified. All the results obtained in the present study will be helpful for follow-up bio-function analysis of BcUGT3 and BcUGT6.

Design principle and method of customized hip stem prosthesis based on X-ray films / 医用生物力学

Objective To introduce the design principles and functional modules of a self-programmed software system for designing customized hip stem prosthesis based on X-ray films. Methods Some femoral anatomical feature points (e.g. the peak of trochanter minor, the center of femoral head, trochanteric fossa), two planned points on osteotomy line (a boundary point at the side of trochanter major and the lowest point on the osteotomy line), and some key location points for designing (e.g. the hip stem far-end location point, the highest point of neck shaft connecting section) were extracted from X-ray films by using image processing methods to predict the patient’s proximal femoral cavities. The customized hip stem prosthesis was designed by inputting the design parameters (e.g. the neck-shaft angle, anteversion angle, thickness of reserved cancellous bone, radiuses of the cross-section in matching area of the prosthesis, height of transition area of the prosthesis). Two-dimensional cross-section verification on matching area of the customized hip stem prosthesis and three-dimensional overall verification were conducted. Results According to the verification results, the design parameters were adjusted to regenerate point cloud data of the hip stem prosthesis model, which could make the designed hip stem prosthesis match the patient’s femoral cavity and finally meet the requirements for the customized purpose. Conclusions The program system introduced in this paper can be used to design customized hip stem prostheses for patients. With the much shorter design cycle and relatively lower cost, this program system can promote the application of customized hip stem prosthesis in clinic and further prove the life quality of patients.